reverted:
--- b/modules/contrib/datetime_extras/Add_datetime_range_formatter_2834016_4.patch
+++ /dev/null
@@ -1,394 +0,0 @@
-diff --git a/datetime_extras.info.yml b/datetime_extras.info.yml
-new file mode 100644
-index 0000000..4c20faf
---- /dev/null
-+++ b/datetime_extras.info.yml
-@@ -0,0 +1,9 @@
-+name: 'Datetime Extras'
-+type: module
-+description: 'Provides the extra widgets and formatters for datetime module.'
-+package: Custom
-+version: 8.0-dev
-+core: 8.x
-+dependencies:
-+  - datetime
-+  - datetime_range
-diff --git a/datetime_extras.module b/datetime_extras.module
-new file mode 100644
-index 0000000..af825ed
---- /dev/null
-+++ b/datetime_extras.module
-@@ -0,0 +1,28 @@
-+<?php
-+
-+/**
-+ * @file
-+ * Field hooks to implement a datetime field widgets and formatters.
-+ */
-+
-+use Drupal\Core\Routing\RouteMatchInterface;
-+
-+/**
-+ * Implements hook_help().
-+ */
-+function datetime_extras_help($route_name, RouteMatchInterface $route_match) {
-+  switch ($route_name) {
-+    case 'help.page.datetime_extras':
-+      $output = '';
-+      $output .= '<h3>' . t('About') . '</h3>';
-+      $output .= '<p>' . t('The Datetime Range module provides a Date field that stores start dates and times, as well as end dates and times. See the <a href=":field">Field module help</a> and the <a href=":field_ui">Field UI module help</a> pages for general information on fields and how to create and manage them. For more information, see the <a href=":datetime_do">online documentation for the Datetime Range module</a>.', array(':field' => \Drupal::url('help.page', array('name' => 'field')), ':field_ui' => (\Drupal::moduleHandler()->moduleExists('field_ui')) ? \Drupal::url('help.page', array('name' => 'field_ui')) : '#', ':datetime_do' => 'https://www.drupal.org/documentation/modules/datetime_range')) . '</p>';
-+      $output .= '<h3>' . t('Uses') . '</h3>';
-+      $output .= '<dl>';
-+      $output .= '<dt>' . t('Managing and displaying date fields') . '</dt>';
-+      $output .= '<dd>' . t('The <em>settings</em> and the <em>display</em> of the Date field can be configured separately. See the <a href=":field_ui">Field UI help</a> for more information on how to manage fields and their display.', array(':field_ui' => (\Drupal::moduleHandler()->moduleExists('field_ui')) ? \Drupal::url('help.page', array('name' => 'field_ui')) : '#')) . '</dd>';
-+      $output .= '<dt>' . t('Displaying dates') . '</dt>';
-+      $output .= '<dd>' . t('Dates can be displayed using the <em>Plain</em> or the <em>Default</em> formatter. The <em>Plain</em> formatter displays the date in the <a href="http://en.wikipedia.org/wiki/ISO_8601">ISO 8601</a> format. If you choose the <em>Default</em> formatter, you can choose a format from a predefined list that can be managed on the <a href=":date_format_list">Date and time formats</a> page.', array(':date_format_list' => \Drupal::url('entity.date_format.collection'))) . '</dd>';
-+      $output .= '</dl>';
-+      return $output;
-+  }
-+}
-diff --git a/src/DateTimeExtraTrait.php b/src/DateTimeExtraTrait.php
-new file mode 100644
-index 0000000..4303d2b
---- /dev/null
-+++ b/src/DateTimeExtraTrait.php
-@@ -0,0 +1,50 @@
-+<?php
-+
-+namespace Drupal\datetime_extras;
-+
-+use Drupal\Core\Datetime\DrupalDateTime;
-+use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
-+
-+/**
-+ * Provides friendly methods for datetime range.
-+ */
-+trait DateTimeExtraTrait {
-+
-+  /**
-+   * Creates a render array from a date object with ISO date attribute.
-+   *
-+   * @param \Drupal\Core\Datetime\DrupalDateTime $date
-+   *   A date object.
-+   *
-+   * @return array
-+   *   A render array.
-+   */
-+  protected function buildDateWithIsoAttribute(DrupalDateTime $date, $format) {
-+    if ($this->getFieldSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE) {
-+      // A date without time will pick up the current time, use the default.
-+      datetime_date_default_time($date);
-+    }
-+
-+    // Create the ISO date in Universal Time.
-+    $iso_date = $date->format("Y-m-d\TH:i:s") . 'Z';
-+
-+    $this->setTimeZone($date);
-+
-+    $build = [
-+      '#theme' => 'time',
-+      '#text' => $this->formatDate($date, $format),
-+      '#html' => FALSE,
-+      '#attributes' => [
-+        'datetime' => $iso_date,
-+      ],
-+      '#cache' => [
-+        'contexts' => [
-+          'timezone',
-+        ],
-+      ],
-+    ];
-+
-+    return $build;
-+  }
-+
-+}
-diff --git a/src/Plugin/Field/FieldFormatter/DateRangeNiceFormatter.php b/src/Plugin/Field/FieldFormatter/DateRangeNiceFormatter.php
-new file mode 100644
-index 0000000..e55f93f
---- /dev/null
-+++ b/src/Plugin/Field/FieldFormatter/DateRangeNiceFormatter.php
-@@ -0,0 +1,176 @@
-+<?php
-+
-+namespace Drupal\datetime_extras\Plugin\Field\FieldFormatter;
-+
-+use Drupal\Core\Datetime\DrupalDateTime;
-+use Drupal\Core\Field\FieldItemListInterface;
-+use Drupal\Core\Form\FormStateInterface;
-+use Drupal\datetime\Plugin\Field\FieldFormatter\DateTimeDefaultFormatter;
-+use Drupal\datetime_extras\DateTimeExtraTrait;
-+
-+/**
-+ * Plugin implementation of the 'Default' formatter for 'daterange' fields.
-+ *
-+ * This formatter renders the data range using <time> elements, with
-+ * configurable date formats (from the list of configured formats) and a
-+ * separator.
-+ *
-+ * @FieldFormatter(
-+ *   id = "daterange_nice",
-+ *   label = @Translation("Nice"),
-+ *   field_types = {
-+ *     "daterange"
-+ *   }
-+ * )
-+ */
-+class DateRangeNiceFormatter extends DateTimeDefaultFormatter {
-+
-+  use DateTimeExtraTrait;
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public static function defaultSettings() {
-+    return [
-+      'separator' => '-',
-+    ] + parent::defaultSettings();
-+  }
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public function viewElements(FieldItemListInterface $items, $langcode) {
-+    $elements = [];
-+    $separator = $this->getSetting('separator');
-+
-+    foreach ($items as $delta => $item) {
-+      if (!empty($item->start_date) && !empty($item->end_date)) {
-+        /** @var \Drupal\Core\Datetime\DrupalDateTime $start_date */
-+        $start_date = $item->start_date;
-+        /** @var \Drupal\Core\Datetime\DrupalDateTime $end_date */
-+        $end_date = $item->end_date;
-+        $format_types = $this->niceFormats();
-+
-+        if ($start_date->format('U') !== $end_date->format('U')) {
-+          $format_start =
-+          $format_end = $format_types[$this->getSetting('format_type')]['format'];
-+          if ($start_date->format('Y-m-d') == $end_date->format('Y-m-d')) {
-+            $format_start = $format_types[$this->getSetting('format_type')]['format_time_start'];
-+            $format_end = $format_types[$this->getSetting('format_type')]['format_time_end'];
-+          }
-+          else if ($start_date->format('Y-m') == $end_date->format('Y-m')) {
-+            $format_start = $format_types[$this->getSetting('format_type')]['format_day_start'];
-+            $format_end = $format_types[$this->getSetting('format_type')]['format_day_end'];
-+          }
-+          else if ($start_date->format('Y') == $end_date->format('Y')) {
-+            $format_start = $format_types[$this->getSetting('format_type')]['format_month_start'];
-+            $format_end = $format_types[$this->getSetting('format_type')]['format_month_end'];
-+          }
-+          else {
-+            $format_start = $format_types[$this->getSetting('format_type')]['format_year_start'];
-+            $format_end = $format_types[$this->getSetting('format_type')]['format_year_end'];
-+          }
-+          $elements[$delta] = [
-+            'start_date' => $this->buildDateWithIsoAttribute($start_date, $format_start),
-+            'separator' => ['#plain_text' => ' ' . $separator . ' '],
-+            'end_date' => $this->buildDateWithIsoAttribute($end_date, $format_end),
-+          ];
-+        }
-+        else {
-+          if (!empty($item->_attributes)) {
-+            $elements[$delta]['#attributes'] += $item->_attributes;
-+            // Unset field item attributes since they have been included in the
-+            // formatter output and should not be rendered in the field template.
-+            unset($item->_attributes);
-+          }
-+        }
-+      }
-+    }
-+
-+    return $elements;
-+  }
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  protected function formatDate($date, $format = NULL) {
-+    $format_type = 'custom';
-+    $format = $format ? $format : 'm/d/Y';
-+    $timezone = $this->getSetting('timezone_override') ?: $date->getTimezone()->getName();
-+    return $this->dateFormatter->format($date->getTimestamp(), $format_type, $format, $timezone != '' ? $timezone : NULL);
-+  }
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public function settingsForm(array $form, FormStateInterface $form_state) {
-+    $form = parent::settingsForm($form, $form_state);
-+
-+    $time = new DrupalDateTime();
-+    $format_types = $this->niceFormats();
-+    $options = [];
-+    foreach ($format_types as $type => $type_info) {
-+      $format = $this->dateFormatter->format($time->format('U'), 'custom', $type_info['format']);
-+      $options[$type] = $type_info['label'] . ' (' . $format . ')';
-+    }
-+
-+    $form['format_type'] = array(
-+      '#type' => 'select',
-+      '#title' => t('Date format'),
-+      '#description' => t("Choose a format for displaying the date. Be sure to set a format appropriate for the field, i.e. omitting time for a field that only has a date."),
-+      '#options' => $options,
-+      '#default_value' => $this->getSetting('format_type'),
-+    );
-+
-+    $form['separator'] = [
-+      '#type' => 'textfield',
-+      '#title' => $this->t('Date separator'),
-+      '#description' => $this->t('The string to separate the start and end dates'),
-+      '#default_value' => $this->getSetting('separator'),
-+    ];
-+    return $form;
-+  }
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public function settingsSummary() {
-+    $summary = parent::settingsSummary();
-+
-+    if ($separator = $this->getSetting('separator')) {
-+      $summary[] = $this->t('Separator: %separator', ['%separator' => $separator]);
-+    }
-+
-+    return $summary;
-+  }
-+
-+  public function niceFormats() {
-+    $formats = [];
-+    $formats['nice_long'] = [
-+      'label' => t('Nice long'),
-+      'format' => 'F d, Y - h:i A',
-+      'format_time_start' => 'F d, Y - h:i A',
-+      'format_time_end' => 'h:i A',
-+      'format_day_start' => 'F d',
-+      'format_day_end' => 'd, Y',
-+      'format_month_start' => 'F d',
-+      'format_month_end' => 'F d, Y',
-+      'format_year_start' => 'F d, Y',
-+      'format_year_end' => 'F d, Y',
-+    ];
-+    $formats['nice_short'] = [
-+      'label' => t('Nice short'),
-+      'format' => 'm/d/Y - h:i a',
-+      'format_time_start' => 'm/d/Y - h:i a',
-+      'format_time_end' => 'h:i a',
-+      'format_day_start' => 'm/d',
-+      'format_day_end' => 'd/Y',
-+      'format_month_start' => 'm/d',
-+      'format_month_end' => 'm/d/Y',
-+      'format_year_start' => 'm/d/Y',
-+      'format_year_end' => 'm/d/Y',
-+    ];
-+    return $formats;
-+  }
-+
-+}
-diff --git a/src/Plugin/Field/FieldWidget/DateRangeNiceWidget.php b/src/Plugin/Field/FieldWidget/DateRangeNiceWidget.php
-new file mode 100644
-index 0000000..da74eb3
---- /dev/null
-+++ b/src/Plugin/Field/FieldWidget/DateRangeNiceWidget.php
-@@ -0,0 +1,101 @@
-+<?php
-+
-+namespace Drupal\datetime_extras\Plugin\Field\FieldWidget;
-+
-+use Drupal\Core\Entity\EntityStorageInterface;
-+use Drupal\Core\Field\FieldDefinitionInterface;
-+use Drupal\Core\Field\FieldItemListInterface;
-+use Drupal\Core\Form\FormStateInterface;
-+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
-+use Drupal\datetime_range\Plugin\Field\FieldType\DateRangeItem;
-+use Symfony\Component\DependencyInjection\ContainerInterface;
-+
-+/**
-+ * Plugin implementation of the 'daterange_nice' widget.
-+ *
-+ * @FieldWidget(
-+ *   id = "daterange_nice",
-+ *   label = @Translation("Nice date and time range"),
-+ *   field_types = {
-+ *     "daterange"
-+ *   }
-+ * )
-+ */
-+class DateRangeNiceWidget extends DateRangeWidgetBase implements ContainerFactoryPluginInterface {
-+
-+  /**
-+   * The date format storage.
-+   *
-+   * @var \Drupal\Core\Entity\EntityStorageInterface
-+   */
-+  protected $dateStorage;
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, array $third_party_settings, EntityStorageInterface $date_storage) {
-+    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $third_party_settings);
-+
-+    $this->dateStorage = $date_storage;
-+  }
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
-+    return new static(
-+      $plugin_id,
-+      $plugin_definition,
-+      $configuration['field_definition'],
-+      $configuration['settings'],
-+      $configuration['third_party_settings'],
-+      $container->get('entity_type.manager')->getStorage('date_format')
-+    );
-+  }
-+
-+  /**
-+   * {@inheritdoc}
-+   */
-+  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
-+    $element = parent::formElement($items, $delta, $element, $form, $form_state);
-+
-+    // Identify the type of date and time elements to use.
-+    switch ($this->getFieldSetting('datetime_type')) {
-+      case DateRangeItem::DATETIME_TYPE_DATE:
-+      case DateRangeItem::DATETIME_TYPE_ALLDAY:
-+        $date_type = 'date';
-+        $time_type = 'none';
-+        $date_format = $this->dateStorage->load('html_date')->getPattern();
-+        $time_format = '';
-+        break;
-+
-+      default:
-+        $date_type = 'date';
-+        $time_type = 'time';
-+        $date_format = $this->dateStorage->load('html_date')->getPattern();
-+        $time_format = $this->dateStorage->load('html_time')->getPattern();
-+        break;
-+    }
-+
-+    $element['value'] += [
-+      '#date_date_format' => $date_format,
-+      '#date_date_element' => $date_type,
-+      '#date_date_callbacks' => [],
-+      '#date_time_format' => $time_format,
-+      '#date_time_element' => $time_type,
-+      '#date_time_callbacks' => [],
-+    ];
-+
-+    $element['end_value'] += [
-+      '#date_date_format' => $date_format,
-+      '#date_date_element' => $date_type,
-+      '#date_date_callbacks' => [],
-+      '#date_time_format' => $time_format,
-+      '#date_time_element' => $time_type,
-+      '#date_time_callbacks' => [],
-+    ];
-+
-+    return $element;
-+  }
-+
-+}
reverted:
--- b/modules/contrib/datetime_extras/config/install/datetime_extras.datetime_extras_range_format.medium.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-langcode: en
-status: true
-dependencies: {  }
-id: medium
-label: Medium
-date_settings:
-  default_pattern: 'j F Y'
-  separator: '–'
-  same_month_start_pattern: j
-  same_month_end_pattern: 'j F Y'
-  same_year_start_pattern: 'j F'
-  same_year_end_pattern: 'j F Y'
-datetime_settings:
-  default_pattern: 'j F Y H:i'
-  separator: '–'
-  same_day_start_pattern: 'j F Y H:i'
-  same_day_end_pattern: 'H:i'
reverted:
--- b/modules/contrib/datetime_extras/config/schema/datetime_extras.schema.yml
+++ /dev/null
@@ -1,58 +0,0 @@
-datetime_extras.datetime_extras_range_format.*:
-  type: config_entity
-  label: 'Date range format config'
-  mapping:
-    id:
-      type: string
-      label: 'ID'
-    label:
-      type: label
-      label: 'Label'
-
-    date_settings:
-      type: mapping
-      label: 'Date settings'
-      mapping:
-        default_pattern:
-          type: string
-          label: 'Default pattern'
-        separator:
-          type: string
-          label: 'Separator'
-        same_month_start_pattern:
-          type: string
-          label: 'Same month start pattern'
-        same_month_end_pattern:
-          type: string
-          label: 'Same month end pattern'
-        same_year_start_pattern:
-          type: string
-          label: 'Same year start pattern'
-        same_year_end_pattern:
-          type: string
-          label: 'Same year end pattern'
-
-    datetime_settings:
-      type: mapping
-      label: 'Datetime settings'
-      mapping:
-        default_pattern:
-          type: string
-          label: 'Default pattern'
-        separator:
-          type: string
-          label: 'Separator'
-        same_day_start_pattern:
-          type: string
-          label: 'Same day start pattern'
-        same_day_end_pattern:
-          type: string
-          label: 'Same day end pattern'
-
-field.formatter.settings.datetime_extras:
-  type: mapping
-  label: 'Date/time range display format settings'
-  mapping:
-    format_type:
-      type: string
-      label: 'Date/time range format'
reverted:
--- b/modules/contrib/datetime_extras/datetime_extras.links.action.yml
+++ /dev/null
@@ -1,5 +0,0 @@
-entity.datetime_extras_range_format.add_form:
-  route_name: 'entity.datetime_extras_range_format.add_form'
-  title: 'Add format'
-  appears_on:
-    - entity.datetime_extras_range_format.collection
reverted:
--- b/modules/contrib/datetime_extras/datetime_extras.links.menu.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-entity.datetime_extras_range_format.collection:
-  title: 'Date and time range formats'
-  route_name: entity.datetime_extras_range_format.collection
-  description: 'Configure how date and time ranges are displayed.'
-  parent: system.admin_config_regional
-  weight: 0
reverted:
--- b/modules/contrib/datetime_extras/datetime_extras.services.yml
+++ /dev/null
@@ -1,4 +0,0 @@
-services:
-  datetime_extras.date_range.formatter:
-    class: Drupal\datetime_extras\DateRangeFormatter
-    arguments: ['@entity_type.manager', '@date.formatter']
reverted:
--- b/modules/contrib/datetime_extras/src/DateRangeFormatListBuilder.php
+++ /dev/null
@@ -1,151 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras;
-
-use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
-use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Entity\EntityTypeInterface;
-use Drupal\datetime_extras\Entity\DateRangeFormatInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
-/**
- * Provides a listing of date range format entities.
- */
-class DateRangeFormatListBuilder extends ConfigEntityListBuilder {
-
-  /**
-   * The date range formatter service.
-   *
-   * @var \Drupal\datetime_extras\DateRangeFormatterInterface
-   */
-  protected $dateRangeFormatter;
-
-  /**
-   * Constructs a new DateFormatListBuilder object.
-   *
-   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
-   *   The entity type definition.
-   * @param \Drupal\Core\Entity\EntityStorageInterface $storage
-   *   The entity storage class.
-   * @param \Drupal\datetime_extras\DateRangeFormatterInterface $date_range_formatter
-   *   The date formatter service.
-   */
-  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, DateRangeFormatterInterface $date_range_formatter) {
-    parent::__construct($entity_type, $storage);
-    $this->dateRangeFormatter = $date_range_formatter;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
-    return new static(
-      $entity_type,
-      $container->get('entity.manager')->getStorage($entity_type->id()),
-      $container->get('datetime_extras.date_range.formatter')
-    );
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function buildHeader() {
-    $header['label'] = $this->t('Name');
-    $header['date'] = $this->t('Date examples');
-    $header['datetime'] = $this->t('Date & time examples');
-    return $header + parent::buildHeader();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function buildRow(EntityInterface $entity) {
-    /** @var \Drupal\datetime_extras\Entity\DateRangeFormatInterface $format */
-    $format = $entity;
-
-    $row['label'] = $format->label();
-    $row['date']['data'] = $this->dateExamples($format);
-    $row['datetime']['data'] = $this->dateTimeExamples($format);
-    return $row + parent::buildRow($entity);
-  }
-
-  /**
-   * Examples of various date ranges shown using the given format.
-   *
-   * @param \Drupal\datetime_extras\Entity\DateRangeFormatInterface $format
-   *   The date range format entity.
-   *
-   * @return array
-   *   A render array suitable for use within the list builder table.
-   */
-  private function dateExamples(DateRangeFormatInterface $format) {
-    $examples = [];
-
-    // An example range that is a single day.
-    $same_day_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-01')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateRange(
-      $same_day_timestamp, $same_day_timestamp, $format->id());
-
-    // An example range that spans several days within the same month.
-    $same_month_start_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-02')->getTimestamp();
-    $same_month_end_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-03')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateRange(
-      $same_month_start_timestamp, $same_month_end_timestamp, $format->id());
-
-    // An example range that spans several months within the same year.
-    $same_year_start_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-04')->getTimestamp();
-    $same_year_end_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-02-05')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateRange(
-      $same_year_start_timestamp, $same_year_end_timestamp, $format->id());
-
-    // An example range that spans multiple years.
-    $fallback_start_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-06')->getTimestamp();
-    $fallback_end_timestamp = \DateTime::createFromFormat('Y-m-d', '2018-01-07')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateRange(
-      $fallback_start_timestamp, $fallback_end_timestamp, $format->id());
-
-    $output = '';
-    foreach ($examples as $example) {
-      $output .= htmlspecialchars($example) . '<br>';
-    }
-    return ['#markup' => $output];
-  }
-
-  /**
-   * Examples of various datetime ranges shown using the given format.
-   *
-   * @param \Drupal\datetime_extras\Entity\DateRangeFormatInterface $format
-   *   The date range format entity.
-   *
-   * @return array
-   *   A render array suitable for use within the list builder table.
-   */
-  private function dateTimeExamples(DateRangeFormatInterface $format) {
-    $examples = [];
-
-    // An example range that is a single date and time.
-    $same_time_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 09:00')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateTimeRange(
-      $same_time_timestamp, $same_time_timestamp, $format->id());
-
-    // An example range that is contained within a single day.
-    $same_day_start_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 09:00')->getTimestamp();
-    $same_day_end_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 13:00')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateTimeRange(
-      $same_day_start_timestamp, $same_day_end_timestamp, $format->id());
-
-    // An example range that spans multiple days.
-    $fallback_start_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 09:00')->getTimestamp();
-    $fallback_end_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-02 13:00')->getTimestamp();
-    $examples[] = $this->dateRangeFormatter->formatDateTimeRange(
-      $fallback_start_timestamp, $fallback_end_timestamp, $format->id());
-
-    $output = '';
-    foreach ($examples as $example) {
-      $output .= htmlspecialchars($example) . '<br>';
-    }
-    return ['#markup' => $output];
-  }
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/DateRangeFormatter.php
+++ /dev/null
@@ -1,135 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras;
-
-use Drupal\Core\Datetime\DateFormatterInterface;
-use Drupal\Core\Datetime\DrupalDateTime;
-use Drupal\Core\Entity\EntityTypeManagerInterface;
-
-/**
- * Provides a service to handle formatting of date/time ranges.
- */
-class DateRangeFormatter implements DateRangeFormatterInterface {
-
-  /**
-   * The date range format storage.
-   *
-   * @var \Drupal\Core\Entity\EntityStorageInterface
-   */
-  protected $dateRangeFormatStorage;
-
-  /**
-   * The core date formatter.
-   *
-   * @var \Drupal\Core\Datetime\DateFormatterInterface
-   */
-  protected $dateFormatter;
-
-  /**
-   * Constructs the date range formatter service.
-   *
-   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
-   *   The entity manager.
-   * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
-   *   The core date formatter.
-   */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, DateFormatterInterface $date_formatter) {
-    $this->dateRangeFormatStorage = $entity_type_manager->getStorage('datetime_extras_range_format');
-    $this->dateFormatter = $date_formatter;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function formatDateRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL) {
-    $start_date_time = DrupalDateTime::createFromTimestamp($start_timestamp, $timezone);
-    $end_date_time = DrupalDateTime::createFromTimestamp($end_timestamp, $timezone);
-
-    /** @var \Drupal\datetime_extras\Entity\DateRangeFormatInterface $entity */
-    $entity = $this->dateRangeFormatStorage->load($type);
-    $date_settings = $entity->getDateSettings();
-    $default_pattern = $date_settings['default_pattern'];
-    $separator = $date_settings['separator'] ?: '';
-
-    // Strings containing the ISO-8601 representations of the start and end
-    // date can be used to determine if the day, month or year is the same.
-    $start_iso_8601 = $start_date_time->format('Y-m-d');
-    $end_iso_8601 = $end_date_time->format('Y-m-d');
-
-    if ($start_iso_8601 === $end_iso_8601) {
-      // The range is a single day.
-      return $this->dateFormatter->format($start_timestamp, 'custom',
-        $default_pattern, $timezone, $langcode);
-    }
-    elseif (substr($start_iso_8601, 0, 7) === substr($end_iso_8601, 0, 7)) {
-      // The range spans several days within the same month.
-      $start_pattern = isset($date_settings['same_month_start_pattern']) ? $date_settings['same_month_start_pattern'] : '';
-      $end_pattern = isset($date_settings['same_month_end_pattern']) ? $date_settings['same_month_end_pattern'] : '';
-      if ($start_pattern && $end_pattern) {
-        $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $start_pattern, $timezone, $langcode);
-        $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $end_pattern, $timezone, $langcode);
-        return $start_text . $separator . $end_text;
-      }
-    }
-    elseif (substr($start_iso_8601, 0, 4) === substr($end_iso_8601, 0, 4)) {
-      // The range spans several months within the same year.
-      $start_pattern = isset($date_settings['same_year_start_pattern']) ? $date_settings['same_year_start_pattern'] : '';
-      $end_pattern = isset($date_settings['same_year_end_pattern']) ? $date_settings['same_year_end_pattern'] : '';
-      if ($start_pattern && $end_pattern) {
-        $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $start_pattern, $timezone, $langcode);
-        $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $end_pattern, $timezone, $langcode);
-        return $start_text . $separator . $end_text;
-      }
-    }
-
-    // Fallback: show the start and end dates in full using the default
-    // pattern. This is the case if the range spans different years,
-    // or if the other patterns are not specified.
-    $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $default_pattern, $timezone, $langcode);
-    $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $default_pattern, $timezone, $langcode);
-    return $start_text . $separator . $end_text;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function formatDateTimeRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL) {
-    $start_date_time = DrupalDateTime::createFromTimestamp($start_timestamp, $timezone);
-    $end_date_time = DrupalDateTime::createFromTimestamp($end_timestamp, $timezone);
-
-    /** @var \Drupal\datetime_extras\Entity\DateRangeFormatInterface $entity */
-    $entity = $this->dateRangeFormatStorage->load($type);
-    $datetime_settings = $entity->getDateTimeSettings();
-    $default_pattern = $datetime_settings['default_pattern'];
-    $separator = $datetime_settings['separator'] ?: '';
-
-    // Strings containing the ISO-8601 representations of the start and end
-    // datetime can be used to determine if the date and/or time are the same.
-    $start_iso_8601 = $start_date_time->format('Y-m-d\TH:i:s');
-    $end_iso_8601 = $end_date_time->format('Y-m-d\TH:i:s');
-
-    if ($start_iso_8601 === $end_iso_8601) {
-      // The range is a single date and time.
-      return $this->dateFormatter->format($start_timestamp, 'custom',
-          $default_pattern, $timezone, $langcode);
-    }
-    elseif (substr($start_iso_8601, 0, 10) == substr($end_iso_8601, 0, 10)) {
-      // The range is contained within a single day.
-      $start_pattern = isset($datetime_settings['same_day_start_pattern']) ? $datetime_settings['same_day_start_pattern'] : '';
-      $end_pattern = isset($datetime_settings['same_day_end_pattern']) ? $datetime_settings['same_day_end_pattern'] : '';
-      if ($start_pattern && $end_pattern) {
-        $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $start_pattern, $timezone, $langcode);
-        $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $end_pattern, $timezone, $langcode);
-        return $start_text . $separator . $end_text;
-      }
-    }
-
-    // Fallback: show the start and end datetimes in full using the default
-    // pattern. This is the case if the range spans different days,
-    // or if the other patterns are not specified.
-    $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $default_pattern, $timezone, $langcode);
-    $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $default_pattern, $timezone, $langcode);
-    return $start_text . $separator . $end_text;
-  }
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/DateRangeFormatterInterface.php
+++ /dev/null
@@ -1,66 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras;
-
-/**
- * Provides an interface defining a date range formatter.
- *
- * @package Drupal\datetime_extras
- */
-interface DateRangeFormatterInterface {
-
-  /**
-   * Formats a date range, using a datetime range format type.
-   *
-   * @param int $start_timestamp
-   *   A UNIX timestamp representing the start time.
-   * @param int $end_timestamp
-   *   A UNIX timestamp representing the end time.
-   * @param string $type
-   *   (optional) The format to use, one of:
-   *   - One of the built-in formats: 'short', 'medium', 'long'.
-   *   - The machine name of an administrator-defined datetime range format.
-   *   Defaults to 'medium'.
-   * @param string|null $timezone
-   *   (optional) Time zone identifier, as described at
-   *   http://php.net/manual/timezones.php Defaults to the time zone used to
-   *   display the page.
-   * @param string|null $langcode
-   *   (optional) Language code to translate to. NULL (default) means to use
-   *   the user interface language for the page.
-   *
-   * @return string
-   *   A translated date & time range string in the requested format.
-   *   Since the format may contain user input, this value should be escaped
-   *   when output.
-   */
-  public function formatDateRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL);
-
-  /**
-   * Formats a date and time range, using a datetime range format type.
-   *
-   * @param int $start_timestamp
-   *   A UNIX timestamp representing the start time.
-   * @param int $end_timestamp
-   *   A UNIX timestamp representing the end time.
-   * @param string $type
-   *   (optional) The format to use, one of:
-   *   - One of the built-in formats: 'short', 'medium', 'long'.
-   *   - The machine name of an administrator-defined datetime range format.
-   *   Defaults to 'medium'.
-   * @param string|null $timezone
-   *   (optional) Time zone identifier, as described at
-   *   http://php.net/manual/timezones.php Defaults to the time zone used to
-   *   display the page.
-   * @param string|null $langcode
-   *   (optional) Language code to translate to. NULL (default) means to use
-   *   the user interface language for the page.
-   *
-   * @return string
-   *   A translated date & time range string in the requested format.
-   *   Since the format may contain user input, this value should be escaped
-   *   when output.
-   */
-  public function formatDateTimeRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL);
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/Entity/DateRangeFormat.php
+++ /dev/null
@@ -1,78 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras\Entity;
-
-use Drupal\Core\Config\Entity\ConfigEntityBase;
-
-/**
- * Defines the date range format entity.
- *
- * @ConfigEntityType(
- *   id = "datetime_extras_range_format",
- *   label = @Translation("Date range format"),
- *   handlers = {
- *     "list_builder" = "Drupal\datetime_extras\DateRangeFormatListBuilder",
- *     "form" = {
- *       "add" = "Drupal\datetime_extras\Form\DateRangeFormatForm",
- *       "edit" = "Drupal\datetime_extras\Form\DateRangeFormatForm",
- *       "delete" = "Drupal\datetime_extras\Form\DateRangeFormatDeleteForm"
- *     },
- *     "route_provider" = {
- *       "html" = "Drupal\Core\Entity\Routing\AdminHtmlRouteProvider",
- *     },
- *   },
- *   config_prefix = "datetime_extras_range_format",
- *   admin_permission = "administer site configuration",
- *   list_cache_tags = { "rendered" },
- *   entity_keys = {
- *     "id" = "id",
- *     "label" = "label",
- *     "uuid" = "uuid"
- *   },
- *   links = {
- *     "canonical" = "/admin/config/regional/datetime_extras_range_format/{datetime_extras_range_format}",
- *     "add-form" = "/admin/config/regional/datetime_extras_range_format/add",
- *     "edit-form" = "/admin/config/regional/datetime_extras_range_format/{datetime_extras_range_format}/edit",
- *     "delete-form" = "/admin/config/regional/datetime_extras_range_format/{datetime_extras_range_format}/delete",
- *     "collection" = "/admin/config/regional/datetime_extras_range_format"
- *   }
- * )
- */
-class DateRangeFormat extends ConfigEntityBase implements DateRangeFormatInterface {
-
-  /**
-   * The Date range format ID.
-   *
-   * @var string
-   */
-  protected $id;
-
-  /**
-   * The Date range format label.
-   *
-   * @var string
-   */
-  protected $label;
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getDateSettings() {
-    return $this->get('date_settings');
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getDateTimeSettings() {
-    return $this->get('datetime_settings');
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getCacheTagsToInvalidate() {
-    return ['rendered'];
-  }
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/Entity/DateRangeFormatInterface.php
+++ /dev/null
@@ -1,46 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras\Entity;
-
-use Drupal\Core\Config\Entity\ConfigEntityInterface;
-
-/**
- * Provides an interface for defining a date range format.
- */
-interface DateRangeFormatInterface extends ConfigEntityInterface {
-
-  /**
-   * The settings for use when displaying date only ranges.
-   *
-   * @return array
-   *   An array with the following keys:
-   *     - "default_pattern" - the default format pattern, used when the
-   *          start and end values are the same, or the range spans multiple
-   *          years
-   *     - "separator" - the separator string to place in between the
-   *          start and end values
-   *     - "same_day_start_pattern" - the format pattern to use for the
-   *          start date, when the range is contained within a single day
-   *     - "same_day_end_pattern" - the format pattern to use for the
-   *          end date, when the range is contained within a single day
-   */
-  public function getDateSettings();
-
-  /**
-   * The settings for use when displaying date & time ranges.
-   *
-   * @return array
-   *   An array with the following keys:
-   *     - "default_pattern" - the default format pattern, used when the
-   *          start and end values are the same, or the range spans
-   *          multiple days
-   *     - "separator" - the separator string to place in between the
-   *          start and end values
-   *     - "same_day_start_pattern" - the format pattern to use for the
-   *          start date & time, when the range is contained within a single day
-   *     - "same_day_end_pattern" - the format pattern to use for the
-   *          end date & time, when the range is contained within a single day
-   */
-  public function getDateTimeSettings();
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/Form/DateRangeFormatDeleteForm.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras\Form;
-
-use Drupal\Core\Entity\EntityDeleteForm;
-
-/**
- * Provides a form for deleting a date range format.
- *
- * @package Drupal\datetime_extras\Form
- */
-class DateRangeFormatDeleteForm extends EntityDeleteForm {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getQuestion() {
-    return $this->t('Are you sure you want to delete the date range format %name?', ['%name' => $this->entity->label()]);
-  }
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/Form/DateRangeFormatForm.php
+++ /dev/null
@@ -1,223 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras\Form;
-
-use Drupal\Core\Entity\EntityForm;
-use Drupal\Core\Form\FormStateInterface;
-
-/**
- * Provides a form for editing date range formats.
- *
- * @package Drupal\datetime_extras\Form
- */
-class DateRangeFormatForm extends EntityForm {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function form(array $form, FormStateInterface $form_state) {
-    $form = parent::form($form, $form_state);
-
-    /** @var \Drupal\datetime_extras\Entity\DateRangeFormatInterface $format */
-    $format = $this->entity;
-
-    $form['label'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Label'),
-      '#maxlength' => 255,
-      '#default_value' => $format->label(),
-      '#description' => $this->t("Name of the date time range format."),
-      '#required' => TRUE,
-    ];
-
-    $form['id'] = [
-      '#type' => 'machine_name',
-      '#default_value' => $format->id(),
-      '#machine_name' => [
-        'exists' => '\Drupal\datetime_extras\Entity\DateRangeFormat::load',
-      ],
-      '#disabled' => !$format->isNew(),
-    ];
-
-    $date_settings = $format->getDateSettings();
-
-    $form['date'] = [
-      '#type' => 'vertical_tabs',
-      '#title' => $this->t('Date only formats'),
-      '#tree' => FALSE,
-    ];
-
-    $form['date']['basic'] = [
-      '#type' => 'details',
-      '#title' => $this->t('Basic'),
-      '#open' => TRUE,
-      '#weight' => 1,
-      '#group' => 'date',
-      '#description' => $this->t('Basic date format used for single dates, or ranges that cannot be shown in a compact form.'),
-    ];
-
-    $form['date']['basic']['default_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Pattern'),
-      '#default_value' => $date_settings['default_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#required' => TRUE,
-      '#parents' => ['date_settings', 'default_pattern'],
-    ];
-
-    $form['date']['basic']['separator'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Separator'),
-      '#default_value' => $date_settings['separator'] ?: '',
-      '#maxlength' => 100,
-      '#size' => 10,
-      '#description' => $this->t('Text between start and end dates.'),
-      '#required' => FALSE,
-      '#parents' => ['date_settings', 'separator'],
-    ];
-
-    $form['date']['same_month'] = [
-      '#type' => 'details',
-      '#title' => $this->t('Same month'),
-      '#open' => TRUE,
-      '#weight' => 2,
-      '#group' => 'date',
-      '#description' => $this->t('Optional formatting of date ranges that span multiple days within the same month.'),
-    ];
-
-    $form['date']['same_month']['same_month_start_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Start date pattern'),
-      '#default_value' => $date_settings['same_month_start_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#parents' => ['date_settings', 'same_month_start_pattern'],
-    ];
-
-    $form['date']['same_month']['same_month_end_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('End date pattern'),
-      '#default_value' => $date_settings['same_month_end_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#parents' => ['date_settings', 'same_month_end_pattern'],
-    ];
-
-    $form['date']['same_year'] = [
-      '#type' => 'details',
-      '#title' => $this->t('Same year'),
-      '#open' => TRUE,
-      '#weight' => 2,
-      '#group' => 'date',
-      '#description' => $this->t('Optional formatting of date ranges that span multiple months within the same year.'),
-    ];
-
-    $form['date']['same_year']['same_year_start_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Start date pattern'),
-      '#default_value' => $date_settings['same_year_start_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#parents' => ['date_settings', 'same_year_start_pattern'],
-    ];
-
-    $form['date']['same_year']['same_year_end_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('End date pattern'),
-      '#default_value' => $date_settings['same_year_end_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#parents' => ['date_settings', 'same_year_end_pattern'],
-    ];
-
-    $datetime_settings = $format->getDateTimeSettings();
-
-    $form['datetime'] = [
-      '#type' => 'vertical_tabs',
-      '#title' => $this->t('Date & time formats'),
-    ];
-
-    $form['datetime']['basic'] = [
-      '#type' => 'details',
-      '#title' => $this->t('Basic'),
-      '#open' => TRUE,
-      '#weight' => 1,
-      '#group' => 'datetime',
-      '#description' => $this->t('Basic date and time format used for single date/times, or ranges that cannot be shown in a compact form.'),
-    ];
-
-    $form['datetime']['basic']['default_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Pattern'),
-      '#default_value' => $datetime_settings['default_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#required' => TRUE,
-      '#parents' => ['datetime_settings', 'default_pattern'],
-    ];
-
-    $form['datetime']['basic']['separator'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Separator'),
-      '#default_value' => $datetime_settings['separator'] ?: '',
-      '#maxlength' => 100,
-      '#size' => 10,
-      '#description' => $this->t('Text between start and end date/times.'),
-      '#required' => FALSE,
-      '#parents' => ['datetime_settings', 'separator'],
-    ];
-
-    $form['datetime']['same_day'] = [
-      '#type' => 'details',
-      '#title' => $this->t('Same day'),
-      '#open' => TRUE,
-      '#weight' => 2,
-      '#group' => 'datetime',
-      '#description' => $this->t('Optional formatting of time ranges within a single day.'),
-    ];
-
-    $form['datetime']['same_day']['same_day_start_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('Start date/time pattern'),
-      '#default_value' => $datetime_settings['same_day_start_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#parents' => ['datetime_settings', 'same_day_start_pattern'],
-    ];
-
-    $form['datetime']['same_day']['same_day_end_pattern'] = [
-      '#type' => 'textfield',
-      '#title' => $this->t('End date/time pattern'),
-      '#default_value' => $datetime_settings['same_day_end_pattern'] ?: '',
-      '#maxlength' => 100,
-      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
-      '#parents' => ['datetime_settings', 'same_day_end_pattern'],
-    ];
-
-    return $form;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function save(array $form, FormStateInterface $form_state) {
-    $date_range_format = $this->entity;
-    $status = $date_range_format->save();
-
-    switch ($status) {
-      case SAVED_NEW:
-        drupal_set_message($this->t('Created the %label date range format.', [
-          '%label' => $date_range_format->label(),
-        ]));
-        break;
-
-      default:
-        drupal_set_message($this->t('Updated the %label date range format.', [
-          '%label' => $date_range_format->label(),
-        ]));
-    }
-    $form_state->setRedirectUrl($date_range_format->toUrl('collection'));
-  }
-
-}
reverted:
--- b/modules/contrib/datetime_extras/src/Plugin/Field/FieldFormatter/DateRangeCompactFormatter.php
+++ /dev/null
@@ -1,168 +0,0 @@
-<?php
-
-namespace Drupal\datetime_extras\Plugin\Field\FieldFormatter;
-
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Field\FieldDefinitionInterface;
-use Drupal\Core\Field\FieldItemListInterface;
-use Drupal\Core\Field\FormatterBase;
-use Drupal\Core\Form\FormStateInterface;
-use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
-use Drupal\datetime_extras\DateRangeFormatterInterface;
-use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
-/**
- * Plugin implementation of the 'Compact' formatter for 'daterange' fields.
- *
- * This formatter renders the data range using <time> elements, with
- * configurable date formats (from the list of configured formats) and a
- * separator.
- *
- * @FieldFormatter(
- *   id = "datetime_extras",
- *   label = @Translation("Datetime Format"),
- *   field_types = {
- *     "daterange"
- *   }
- * )
- */
-class DateRangeCompactFormatter extends FormatterBase implements ContainerFactoryPluginInterface {
-
-  /**
-   * The date range formatter service.
-   *
-   * @var \Drupal\datetime_extras\DateRangeFormatterInterface
-   */
-  protected $dateRangeFormatter;
-
-  /**
-   * The date range format entity storage.
-   *
-   * @var \Drupal\Core\Entity\EntityStorageInterface
-   */
-  protected $dateRangeFormatStorage;
-
-  /**
-   * Constructs a new DateRangeCompactFormatter.
-   *
-   * @param string $plugin_id
-   *   The plugin_id for the formatter.
-   * @param mixed $plugin_definition
-   *   The plugin implementation definition.
-   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
-   *   The definition of the field to which the formatter is associated.
-   * @param array $settings
-   *   The formatter settings.
-   * @param string $label
-   *   The formatter label display setting.
-   * @param string $view_mode
-   *   The view mode.
-   * @param array $third_party_settings
-   *   Third party settings.
-   * @param \Drupal\datetime_extras\DateRangeFormatterInterface $date_range_formatter
-   *   The date formatter service.
-   * @param \Drupal\Core\Entity\EntityStorageInterface $date_range_format_storage
-   *   The date format entity storage.
-   */
-  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, DateRangeFormatterInterface $date_range_formatter, EntityStorageInterface $date_range_format_storage) {
-    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
-
-    $this->dateRangeFormatter = $date_range_formatter;
-    $this->dateRangeFormatStorage = $date_range_format_storage;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
-    return new static(
-      $plugin_id,
-      $plugin_definition,
-      $configuration['field_definition'],
-      $configuration['settings'],
-      $configuration['label'],
-      $configuration['view_mode'],
-      $configuration['third_party_settings'],
-      $container->get('datetime_extras.date_range.formatter'),
-      $container->get('entity_type.manager')->getStorage('datetime_extras_range_format')
-    );
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function defaultSettings() {
-    return [
-      'format_type' => 'medium',
-    ] + parent::defaultSettings();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function settingsForm(array $form, FormStateInterface $form_state) {
-    $form = parent::settingsForm($form, $form_state);
-
-    $format_types = $this->dateRangeFormatStorage->loadMultiple();
-    $options = [];
-    foreach ($format_types as $type => $type_info) {
-      $options[$type] = $type_info->label();
-    }
-
-    $form['format_type'] = [
-      '#type' => 'select',
-      '#title' => $this->t('Date and time range format'),
-      '#description' => $this->t("Choose a format for displaying the date and time range."),
-      '#options' => $options,
-      '#default_value' => $this->getSetting('format_type'),
-    ];
-
-    return $form;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function settingsSummary() {
-    $summary = parent::settingsSummary();
-    $summary[] = $this->t('Format: @format', ['@format' => $this->getSetting('format_type')]);
-    return $summary;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function viewElements(FieldItemListInterface $items, $langcode) {
-    $elements = [];
-
-    foreach ($items as $delta => $item) {
-      if (!empty($item->start_date) && !empty($item->end_date)) {
-        $start_timestamp = $item->start_date->getTimestamp();
-        $end_timestamp = $item->end_date->getTimestamp();
-        $format = $this->getSetting('format_type');
-
-        if ($this->getFieldSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE) {
-          $timezone = DATETIME_STORAGE_TIMEZONE;
-          $text = $this->dateRangeFormatter->formatDateRange($start_timestamp, $end_timestamp, $format, $timezone);
-        }
-        else {
-          $timezone = drupal_get_user_timezone();
-          $text = $this->dateRangeFormatter->formatDateTimeRange($start_timestamp, $end_timestamp, $format, $timezone);
-        }
-
-        $elements[$delta] = [
-          '#plain_text' => $text,
-          '#cache' => [
-            'contexts' => [
-              'timezone',
-            ],
-          ],
-        ];
-      }
-    }
-
-    return $elements;
-  }
-
-}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/config/install/datetime_extras_daterange.daterange_range_format.medium.yml
@@ -0,0 +1,17 @@
+langcode: en
+status: true
+dependencies: {  }
+id: medium
+label: Medium
+date_settings:
+  default_pattern: 'j F Y'
+  separator: '–'
+  same_month_start_pattern: j
+  same_month_end_pattern: 'j F Y'
+  same_year_start_pattern: 'j F'
+  same_year_end_pattern: 'j F Y'
+datetime_settings:
+  default_pattern: 'j F Y H:i'
+  separator: '–'
+  same_day_start_pattern: 'j F Y H:i'
+  same_day_end_pattern: 'H:i'
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/config/schema/datetime_extras_daterange.schema.yml
@@ -0,0 +1,58 @@
+datetime_extras_daterange.daterange_range_format.*:
+  type: config_entity
+  label: 'Date range format config'
+  mapping:
+    id:
+      type: string
+      label: 'ID'
+    label:
+      type: label
+      label: 'Label'
+
+    date_settings:
+      type: mapping
+      label: 'Date settings'
+      mapping:
+        default_pattern:
+          type: string
+          label: 'Default pattern'
+        separator:
+          type: string
+          label: 'Separator'
+        same_month_start_pattern:
+          type: string
+          label: 'Same month start pattern'
+        same_month_end_pattern:
+          type: string
+          label: 'Same month end pattern'
+        same_year_start_pattern:
+          type: string
+          label: 'Same year start pattern'
+        same_year_end_pattern:
+          type: string
+          label: 'Same year end pattern'
+
+    datetime_settings:
+      type: mapping
+      label: 'Datetime settings'
+      mapping:
+        default_pattern:
+          type: string
+          label: 'Default pattern'
+        separator:
+          type: string
+          label: 'Separator'
+        same_day_start_pattern:
+          type: string
+          label: 'Same day start pattern'
+        same_day_end_pattern:
+          type: string
+          label: 'Same day end pattern'
+
+field.formatter.settings.datetime_extras_daterange:
+  type: mapping
+  label: 'Date/time range display format settings'
+  mapping:
+    format_type:
+      type: string
+      label: 'Date/time range format'
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/datetime_extras_daterange.info.yml
@@ -0,0 +1,6 @@
+name: 'Date Range Formatter'
+type: module
+description: 'Provides a compact formatter for date range fields.'
+core: 8.x
+dependencies:
+  - drupal:datetime_range
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/datetime_extras_daterange.links.action.yml
@@ -0,0 +1,5 @@
+entity.daterange_range_format.add_form:
+  route_name: 'entity.daterange_range_format.add_form'
+  title: 'Add format'
+  appears_on:
+    - entity.daterange_range_format.collection
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/datetime_extras_daterange.links.menu.yml
@@ -0,0 +1,6 @@
+entity.daterange_range_format.collection:
+  title: 'Daterange formats'
+  route_name: entity.daterange_range_format.collection
+  description: 'Configure how date and time ranges are displayed.'
+  parent: system.admin_config_regional
+  weight: 0
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/datetime_extras_daterange.services.yml
@@ -0,0 +1,4 @@
+services:
+  datetime_extras_daterange.date_range.formatter:
+    class: Drupal\datetime_extras_daterange\DateRangeFormatter
+    arguments: ['@entity_type.manager', '@date.formatter']
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/DateRangeFormatListBuilder.php
@@ -0,0 +1,151 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange;
+
+use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a listing of date range format entities.
+ */
+class DateRangeFormatListBuilder extends ConfigEntityListBuilder {
+
+  /**
+   * The date range formatter service.
+   *
+   * @var \Drupal\datetime_extras_daterange\DateRangeFormatterInterface
+   */
+  protected $dateRangeFormatter;
+
+  /**
+   * Constructs a new DateFormatListBuilder object.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type definition.
+   * @param \Drupal\Core\Entity\EntityStorageInterface $storage
+   *   The entity storage class.
+   * @param \Drupal\datetime_extras_daterange\DateRangeFormatterInterface $date_range_formatter
+   *   The date formatter service.
+   */
+  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, DateRangeFormatterInterface $date_range_formatter) {
+    parent::__construct($entity_type, $storage);
+    $this->dateRangeFormatter = $date_range_formatter;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
+    return new static(
+      $entity_type,
+      $container->get('entity.manager')->getStorage($entity_type->id()),
+      $container->get('datetime_extras_daterange.date_range.formatter')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildHeader() {
+    $header['label'] = $this->t('Name');
+    $header['date'] = $this->t('Date examples');
+    $header['datetime'] = $this->t('Date & time examples');
+    return $header + parent::buildHeader();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildRow(EntityInterface $entity) {
+    /** @var \Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface $format */
+    $format = $entity;
+
+    $row['label'] = $format->label();
+    $row['date']['data'] = $this->dateExamples($format);
+    $row['datetime']['data'] = $this->dateTimeExamples($format);
+    return $row + parent::buildRow($entity);
+  }
+
+  /**
+   * Examples of various date ranges shown using the given format.
+   *
+   * @param \Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface $format
+   *   The date range format entity.
+   *
+   * @return array
+   *   A render array suitable for use within the list builder table.
+   */
+  private function dateExamples(DateRangeFormatInterface $format) {
+    $examples = [];
+
+    // An example range that is a single day.
+    $same_day_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-01')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateRange(
+      $same_day_timestamp, $same_day_timestamp, $format->id());
+
+    // An example range that spans several days within the same month.
+    $same_month_start_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-02')->getTimestamp();
+    $same_month_end_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-03')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateRange(
+      $same_month_start_timestamp, $same_month_end_timestamp, $format->id());
+
+    // An example range that spans several months within the same year.
+    $same_year_start_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-04')->getTimestamp();
+    $same_year_end_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-02-05')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateRange(
+      $same_year_start_timestamp, $same_year_end_timestamp, $format->id());
+
+    // An example range that spans multiple years.
+    $fallback_start_timestamp = \DateTime::createFromFormat('Y-m-d', '2017-01-06')->getTimestamp();
+    $fallback_end_timestamp = \DateTime::createFromFormat('Y-m-d', '2018-01-07')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateRange(
+      $fallback_start_timestamp, $fallback_end_timestamp, $format->id());
+
+    $output = '';
+    foreach ($examples as $example) {
+      $output .= htmlspecialchars($example) . '<br>';
+    }
+    return ['#markup' => $output];
+  }
+
+  /**
+   * Examples of various datetime ranges shown using the given format.
+   *
+   * @param \Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface $format
+   *   The date range format entity.
+   *
+   * @return array
+   *   A render array suitable for use within the list builder table.
+   */
+  private function dateTimeExamples(DateRangeFormatInterface $format) {
+    $examples = [];
+
+    // An example range that is a single date and time.
+    $same_time_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 09:00')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateTimeRange(
+      $same_time_timestamp, $same_time_timestamp, $format->id());
+
+    // An example range that is contained within a single day.
+    $same_day_start_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 09:00')->getTimestamp();
+    $same_day_end_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 13:00')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateTimeRange(
+      $same_day_start_timestamp, $same_day_end_timestamp, $format->id());
+
+    // An example range that spans multiple days.
+    $fallback_start_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-01 09:00')->getTimestamp();
+    $fallback_end_timestamp = \DateTime::createFromFormat('Y-m-d H:i', '2017-01-02 13:00')->getTimestamp();
+    $examples[] = $this->dateRangeFormatter->formatDateTimeRange(
+      $fallback_start_timestamp, $fallback_end_timestamp, $format->id());
+
+    $output = '';
+    foreach ($examples as $example) {
+      $output .= htmlspecialchars($example) . '<br>';
+    }
+    return ['#markup' => $output];
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/DateRangeFormatter.php
@@ -0,0 +1,135 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange;
+
+use Drupal\Core\Datetime\DateFormatterInterface;
+use Drupal\Core\Datetime\DrupalDateTime;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+
+/**
+ * Provides a service to handle formatting of date/time ranges.
+ */
+class DateRangeFormatter implements DateRangeFormatterInterface {
+
+  /**
+   * The date range format storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $dateRangeFormatStorage;
+
+  /**
+   * The core date formatter.
+   *
+   * @var \Drupal\Core\Datetime\DateFormatterInterface
+   */
+  protected $dateFormatter;
+
+  /**
+   * Constructs the date range formatter service.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity manager.
+   * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
+   *   The core date formatter.
+   */
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, DateFormatterInterface $date_formatter) {
+    $this->dateRangeFormatStorage = $entity_type_manager->getStorage('daterange_range_format');
+    $this->dateFormatter = $date_formatter;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function formatDateRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL) {
+    $start_date_time = DrupalDateTime::createFromTimestamp($start_timestamp, $timezone);
+    $end_date_time = DrupalDateTime::createFromTimestamp($end_timestamp, $timezone);
+
+    /** @var \Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface $entity */
+    $entity = $this->dateRangeFormatStorage->load($type);
+    $date_settings = $entity->getDateSettings();
+    $default_pattern = $date_settings['default_pattern'];
+    $separator = $date_settings['separator'] ?: '';
+
+    // Strings containing the ISO-8601 representations of the start and end
+    // date can be used to determine if the day, month or year is the same.
+    $start_iso_8601 = $start_date_time->format('Y-m-d');
+    $end_iso_8601 = $end_date_time->format('Y-m-d');
+
+    if ($start_iso_8601 === $end_iso_8601) {
+      // The range is a single day.
+      return $this->dateFormatter->format($start_timestamp, 'custom',
+        $default_pattern, $timezone, $langcode);
+    }
+    elseif (substr($start_iso_8601, 0, 7) === substr($end_iso_8601, 0, 7)) {
+      // The range spans several days within the same month.
+      $start_pattern = isset($date_settings['same_month_start_pattern']) ? $date_settings['same_month_start_pattern'] : '';
+      $end_pattern = isset($date_settings['same_month_end_pattern']) ? $date_settings['same_month_end_pattern'] : '';
+      if ($start_pattern && $end_pattern) {
+        $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $start_pattern, $timezone, $langcode);
+        $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $end_pattern, $timezone, $langcode);
+        return $start_text . $separator . $end_text;
+      }
+    }
+    elseif (substr($start_iso_8601, 0, 4) === substr($end_iso_8601, 0, 4)) {
+      // The range spans several months within the same year.
+      $start_pattern = isset($date_settings['same_year_start_pattern']) ? $date_settings['same_year_start_pattern'] : '';
+      $end_pattern = isset($date_settings['same_year_end_pattern']) ? $date_settings['same_year_end_pattern'] : '';
+      if ($start_pattern && $end_pattern) {
+        $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $start_pattern, $timezone, $langcode);
+        $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $end_pattern, $timezone, $langcode);
+        return $start_text . $separator . $end_text;
+      }
+    }
+
+    // Fallback: show the start and end dates in full using the default
+    // pattern. This is the case if the range spans different years,
+    // or if the other patterns are not specified.
+    $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $default_pattern, $timezone, $langcode);
+    $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $default_pattern, $timezone, $langcode);
+    return $start_text . $separator . $end_text;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function formatDateTimeRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL) {
+    $start_date_time = DrupalDateTime::createFromTimestamp($start_timestamp, $timezone);
+    $end_date_time = DrupalDateTime::createFromTimestamp($end_timestamp, $timezone);
+
+    /** @var \Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface $entity */
+    $entity = $this->dateRangeFormatStorage->load($type);
+    $datetime_settings = $entity->getDateTimeSettings();
+    $default_pattern = $datetime_settings['default_pattern'];
+    $separator = $datetime_settings['separator'] ?: '';
+
+    // Strings containing the ISO-8601 representations of the start and end
+    // datetime can be used to determine if the date and/or time are the same.
+    $start_iso_8601 = $start_date_time->format('Y-m-d\TH:i:s');
+    $end_iso_8601 = $end_date_time->format('Y-m-d\TH:i:s');
+
+    if ($start_iso_8601 === $end_iso_8601) {
+      // The range is a single date and time.
+      return $this->dateFormatter->format($start_timestamp, 'custom',
+          $default_pattern, $timezone, $langcode);
+    }
+    elseif (substr($start_iso_8601, 0, 10) == substr($end_iso_8601, 0, 10)) {
+      // The range is contained within a single day.
+      $start_pattern = isset($datetime_settings['same_day_start_pattern']) ? $datetime_settings['same_day_start_pattern'] : '';
+      $end_pattern = isset($datetime_settings['same_day_end_pattern']) ? $datetime_settings['same_day_end_pattern'] : '';
+      if ($start_pattern && $end_pattern) {
+        $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $start_pattern, $timezone, $langcode);
+        $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $end_pattern, $timezone, $langcode);
+        return $start_text . $separator . $end_text;
+      }
+    }
+
+    // Fallback: show the start and end datetimes in full using the default
+    // pattern. This is the case if the range spans different days,
+    // or if the other patterns are not specified.
+    $start_text = $this->dateFormatter->format($start_timestamp, 'custom', $default_pattern, $timezone, $langcode);
+    $end_text = $this->dateFormatter->format($end_timestamp, 'custom', $default_pattern, $timezone, $langcode);
+    return $start_text . $separator . $end_text;
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/DateRangeFormatterInterface.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange;
+
+/**
+ * Provides an interface defining a date range formatter.
+ *
+ * @package Drupal\datetime_extras_daterange
+ */
+interface DateRangeFormatterInterface {
+
+  /**
+   * Formats a date range, using a datetime range format type.
+   *
+   * @param int $start_timestamp
+   *   A UNIX timestamp representing the start time.
+   * @param int $end_timestamp
+   *   A UNIX timestamp representing the end time.
+   * @param string $type
+   *   (optional) The format to use, one of:
+   *   - One of the built-in formats: 'short', 'medium', 'long'.
+   *   - The machine name of an administrator-defined datetime range format.
+   *   Defaults to 'medium'.
+   * @param string|null $timezone
+   *   (optional) Time zone identifier, as described at
+   *   http://php.net/manual/timezones.php Defaults to the time zone used to
+   *   display the page.
+   * @param string|null $langcode
+   *   (optional) Language code to translate to. NULL (default) means to use
+   *   the user interface language for the page.
+   *
+   * @return string
+   *   A translated date & time range string in the requested format.
+   *   Since the format may contain user input, this value should be escaped
+   *   when output.
+   */
+  public function formatDateRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL);
+
+  /**
+   * Formats a date and time range, using a datetime range format type.
+   *
+   * @param int $start_timestamp
+   *   A UNIX timestamp representing the start time.
+   * @param int $end_timestamp
+   *   A UNIX timestamp representing the end time.
+   * @param string $type
+   *   (optional) The format to use, one of:
+   *   - One of the built-in formats: 'short', 'medium', 'long'.
+   *   - The machine name of an administrator-defined datetime range format.
+   *   Defaults to 'medium'.
+   * @param string|null $timezone
+   *   (optional) Time zone identifier, as described at
+   *   http://php.net/manual/timezones.php Defaults to the time zone used to
+   *   display the page.
+   * @param string|null $langcode
+   *   (optional) Language code to translate to. NULL (default) means to use
+   *   the user interface language for the page.
+   *
+   * @return string
+   *   A translated date & time range string in the requested format.
+   *   Since the format may contain user input, this value should be escaped
+   *   when output.
+   */
+  public function formatDateTimeRange($start_timestamp, $end_timestamp, $type = 'medium', $timezone = NULL, $langcode = NULL);
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/Entity/DateRangeFormat.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange\Entity;
+
+use Drupal\Core\Config\Entity\ConfigEntityBase;
+
+/**
+ * Defines the date range format entity.
+ *
+ * @ConfigEntityType(
+ *   id = "daterange_range_format",
+ *   label = @Translation("Date range format"),
+ *   handlers = {
+ *     "list_builder" = "Drupal\datetime_extras_daterange\DateRangeFormatListBuilder",
+ *     "form" = {
+ *       "add" = "Drupal\datetime_extras_daterange\Form\DateRangeFormatForm",
+ *       "edit" = "Drupal\datetime_extras_daterange\Form\DateRangeFormatForm",
+ *       "delete" = "Drupal\datetime_extras_daterange\Form\DateRangeFormatDeleteForm"
+ *     },
+ *     "route_provider" = {
+ *       "html" = "Drupal\Core\Entity\Routing\AdminHtmlRouteProvider",
+ *     },
+ *   },
+ *   config_prefix = "daterange_range_format",
+ *   admin_permission = "administer site configuration",
+ *   list_cache_tags = { "rendered" },
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "label" = "label",
+ *     "uuid" = "uuid"
+ *   },
+ *   links = {
+ *     "canonical" = "/admin/config/regional/daterange_range_format/{daterange_range_format}",
+ *     "add-form" = "/admin/config/regional/daterange_range_format/add",
+ *     "edit-form" = "/admin/config/regional/daterange_range_format/{daterange_range_format}/edit",
+ *     "delete-form" = "/admin/config/regional/daterange_range_format/{daterange_range_format}/delete",
+ *     "collection" = "/admin/config/regional/daterange_range_format"
+ *   }
+ * )
+ */
+class DateRangeFormat extends ConfigEntityBase implements DateRangeFormatInterface {
+
+  /**
+   * The Date range format ID.
+   *
+   * @var string
+   */
+  protected $id;
+
+  /**
+   * The Date range format label.
+   *
+   * @var string
+   */
+  protected $label;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDateSettings() {
+    return $this->get('date_settings');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDateTimeSettings() {
+    return $this->get('datetime_settings');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheTagsToInvalidate() {
+    return ['rendered'];
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/Entity/DateRangeFormatInterface.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange\Entity;
+
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
+
+/**
+ * Provides an interface for defining a date range format.
+ */
+interface DateRangeFormatInterface extends ConfigEntityInterface {
+
+  /**
+   * The settings for use when displaying date only ranges.
+   *
+   * @return array
+   *   An array with the following keys:
+   *     - "default_pattern" - the default format pattern, used when the
+   *          start and end values are the same, or the range spans multiple
+   *          years
+   *     - "separator" - the separator string to place in between the
+   *          start and end values
+   *     - "same_day_start_pattern" - the format pattern to use for the
+   *          start date, when the range is contained within a single day
+   *     - "same_day_end_pattern" - the format pattern to use for the
+   *          end date, when the range is contained within a single day
+   */
+  public function getDateSettings();
+
+  /**
+   * The settings for use when displaying date & time ranges.
+   *
+   * @return array
+   *   An array with the following keys:
+   *     - "default_pattern" - the default format pattern, used when the
+   *          start and end values are the same, or the range spans
+   *          multiple days
+   *     - "separator" - the separator string to place in between the
+   *          start and end values
+   *     - "same_day_start_pattern" - the format pattern to use for the
+   *          start date & time, when the range is contained within a single day
+   *     - "same_day_end_pattern" - the format pattern to use for the
+   *          end date & time, when the range is contained within a single day
+   */
+  public function getDateTimeSettings();
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/Form/DateRangeFormatDeleteForm.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange\Form;
+
+use Drupal\Core\Entity\EntityDeleteForm;
+
+/**
+ * Provides a form for deleting a date range format.
+ *
+ * @package Drupal\datetime_extras_daterange\Form
+ */
+class DateRangeFormatDeleteForm extends EntityDeleteForm {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getQuestion() {
+    return $this->t('Are you sure you want to delete the date range format %name?', ['%name' => $this->entity->label()]);
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/Form/DateRangeFormatForm.php
@@ -0,0 +1,223 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange\Form;
+
+use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Provides a form for editing date range formats.
+ *
+ * @package Drupal\datetime_extras_daterange\Form
+ */
+class DateRangeFormatForm extends EntityForm {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function form(array $form, FormStateInterface $form_state) {
+    $form = parent::form($form, $form_state);
+
+    /** @var \Drupal\datetime_extras_daterange\Entity\DateRangeFormatInterface $format */
+    $format = $this->entity;
+
+    $form['label'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Label'),
+      '#maxlength' => 255,
+      '#default_value' => $format->label(),
+      '#description' => $this->t("Name of the date time range format."),
+      '#required' => TRUE,
+    ];
+
+    $form['id'] = [
+      '#type' => 'machine_name',
+      '#default_value' => $format->id(),
+      '#machine_name' => [
+        'exists' => '\Drupal\datetime_extras_daterange\Entity\DateRangeFormat::load',
+      ],
+      '#disabled' => !$format->isNew(),
+    ];
+
+    $date_settings = $format->getDateSettings();
+
+    $form['date'] = [
+      '#type' => 'vertical_tabs',
+      '#title' => $this->t('Date only formats'),
+      '#tree' => FALSE,
+    ];
+
+    $form['date']['basic'] = [
+      '#type' => 'details',
+      '#title' => $this->t('Basic'),
+      '#open' => TRUE,
+      '#weight' => 1,
+      '#group' => 'date',
+      '#description' => $this->t('Basic date format used for single dates, or ranges that cannot be shown in a compact form.'),
+    ];
+
+    $form['date']['basic']['default_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Pattern'),
+      '#default_value' => $date_settings['default_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#required' => TRUE,
+      '#parents' => ['date_settings', 'default_pattern'],
+    ];
+
+    $form['date']['basic']['separator'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Separator'),
+      '#default_value' => $date_settings['separator'] ?: '',
+      '#maxlength' => 100,
+      '#size' => 10,
+      '#description' => $this->t('Text between start and end dates.'),
+      '#required' => FALSE,
+      '#parents' => ['date_settings', 'separator'],
+    ];
+
+    $form['date']['same_month'] = [
+      '#type' => 'details',
+      '#title' => $this->t('Same month'),
+      '#open' => TRUE,
+      '#weight' => 2,
+      '#group' => 'date',
+      '#description' => $this->t('Optional formatting of date ranges that span multiple days within the same month.'),
+    ];
+
+    $form['date']['same_month']['same_month_start_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Start date pattern'),
+      '#default_value' => $date_settings['same_month_start_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#parents' => ['date_settings', 'same_month_start_pattern'],
+    ];
+
+    $form['date']['same_month']['same_month_end_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('End date pattern'),
+      '#default_value' => $date_settings['same_month_end_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#parents' => ['date_settings', 'same_month_end_pattern'],
+    ];
+
+    $form['date']['same_year'] = [
+      '#type' => 'details',
+      '#title' => $this->t('Same year'),
+      '#open' => TRUE,
+      '#weight' => 2,
+      '#group' => 'date',
+      '#description' => $this->t('Optional formatting of date ranges that span multiple months within the same year.'),
+    ];
+
+    $form['date']['same_year']['same_year_start_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Start date pattern'),
+      '#default_value' => $date_settings['same_year_start_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#parents' => ['date_settings', 'same_year_start_pattern'],
+    ];
+
+    $form['date']['same_year']['same_year_end_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('End date pattern'),
+      '#default_value' => $date_settings['same_year_end_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#parents' => ['date_settings', 'same_year_end_pattern'],
+    ];
+
+    $datetime_settings = $format->getDateTimeSettings();
+
+    $form['datetime'] = [
+      '#type' => 'vertical_tabs',
+      '#title' => $this->t('Date & time formats'),
+    ];
+
+    $form['datetime']['basic'] = [
+      '#type' => 'details',
+      '#title' => $this->t('Basic'),
+      '#open' => TRUE,
+      '#weight' => 1,
+      '#group' => 'datetime',
+      '#description' => $this->t('Basic date and time format used for single date/times, or ranges that cannot be shown in a compact form.'),
+    ];
+
+    $form['datetime']['basic']['default_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Pattern'),
+      '#default_value' => $datetime_settings['default_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#required' => TRUE,
+      '#parents' => ['datetime_settings', 'default_pattern'],
+    ];
+
+    $form['datetime']['basic']['separator'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Separator'),
+      '#default_value' => $datetime_settings['separator'] ?: '',
+      '#maxlength' => 100,
+      '#size' => 10,
+      '#description' => $this->t('Text between start and end date/times.'),
+      '#required' => FALSE,
+      '#parents' => ['datetime_settings', 'separator'],
+    ];
+
+    $form['datetime']['same_day'] = [
+      '#type' => 'details',
+      '#title' => $this->t('Same day'),
+      '#open' => TRUE,
+      '#weight' => 2,
+      '#group' => 'datetime',
+      '#description' => $this->t('Optional formatting of time ranges within a single day.'),
+    ];
+
+    $form['datetime']['same_day']['same_day_start_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Start date/time pattern'),
+      '#default_value' => $datetime_settings['same_day_start_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#parents' => ['datetime_settings', 'same_day_start_pattern'],
+    ];
+
+    $form['datetime']['same_day']['same_day_end_pattern'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('End date/time pattern'),
+      '#default_value' => $datetime_settings['same_day_end_pattern'] ?: '',
+      '#maxlength' => 100,
+      '#description' => $this->t('A user-defined date format. See the <a href="http://php.net/manual/function.date.php">PHP manual</a> for available options.'),
+      '#parents' => ['datetime_settings', 'same_day_end_pattern'],
+    ];
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function save(array $form, FormStateInterface $form_state) {
+    $date_range_format = $this->entity;
+    $status = $date_range_format->save();
+
+    switch ($status) {
+      case SAVED_NEW:
+        drupal_set_message($this->t('Created the %label date range format.', [
+          '%label' => $date_range_format->label(),
+        ]));
+        break;
+
+      default:
+        drupal_set_message($this->t('Updated the %label date range format.', [
+          '%label' => $date_range_format->label(),
+        ]));
+    }
+    $form_state->setRedirectUrl($date_range_format->toUrl('collection'));
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/modules/contrib/datetime_extras/modules/datetime_extras_daterange/src/Plugin/Field/FieldFormatter/DateRangeCompactFormatter.php
@@ -0,0 +1,168 @@
+<?php
+
+namespace Drupal\datetime_extras_daterange\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\FormatterBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\datetime_extras_daterange\DateRangeFormatterInterface;
+use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Plugin implementation of the 'Compact' formatter for 'daterange' fields.
+ *
+ * This formatter renders the data range using <time> elements, with
+ * configurable date formats (from the list of configured formats) and a
+ * separator.
+ *
+ * @FieldFormatter(
+ *   id = "datetime_extras_daterange",
+ *   label = @Translation("Datetime Format"),
+ *   field_types = {
+ *     "daterange"
+ *   }
+ * )
+ */
+class DateRangeCompactFormatter extends FormatterBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The date range formatter service.
+   *
+   * @var \Drupal\datetime_extras_daterange\DateRangeFormatterInterface
+   */
+  protected $dateRangeFormatter;
+
+  /**
+   * The date range format entity storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $dateRangeFormatStorage;
+
+  /**
+   * Constructs a new DateRangeCompactFormatter.
+   *
+   * @param string $plugin_id
+   *   The plugin_id for the formatter.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
+   *   The definition of the field to which the formatter is associated.
+   * @param array $settings
+   *   The formatter settings.
+   * @param string $label
+   *   The formatter label display setting.
+   * @param string $view_mode
+   *   The view mode.
+   * @param array $third_party_settings
+   *   Third party settings.
+   * @param \Drupal\datetime_extras_daterange\DateRangeFormatterInterface $date_range_formatter
+   *   The date formatter service.
+   * @param \Drupal\Core\Entity\EntityStorageInterface $date_range_format_storage
+   *   The date format entity storage.
+   */
+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, DateRangeFormatterInterface $date_range_formatter, EntityStorageInterface $date_range_format_storage) {
+    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
+
+    $this->dateRangeFormatter = $date_range_formatter;
+    $this->dateRangeFormatStorage = $date_range_format_storage;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $plugin_id,
+      $plugin_definition,
+      $configuration['field_definition'],
+      $configuration['settings'],
+      $configuration['label'],
+      $configuration['view_mode'],
+      $configuration['third_party_settings'],
+      $container->get('datetime_extras_daterange.date_range.formatter'),
+      $container->get('entity_type.manager')->getStorage('daterange_range_format')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'format_type' => 'medium',
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $form = parent::settingsForm($form, $form_state);
+
+    $format_types = $this->dateRangeFormatStorage->loadMultiple();
+    $options = [];
+    foreach ($format_types as $type => $type_info) {
+      $options[$type] = $type_info->label();
+    }
+
+    $form['format_type'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Date and time range format'),
+      '#description' => $this->t("Choose a format for displaying the date and time range."),
+      '#options' => $options,
+      '#default_value' => $this->getSetting('format_type'),
+    ];
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = parent::settingsSummary();
+    $summary[] = $this->t('Format: @format', ['@format' => $this->getSetting('format_type')]);
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = [];
+
+    foreach ($items as $delta => $item) {
+      if (!empty($item->start_date) && !empty($item->end_date)) {
+        $start_timestamp = $item->start_date->getTimestamp();
+        $end_timestamp = $item->end_date->getTimestamp();
+        $format = $this->getSetting('format_type');
+
+        if ($this->getFieldSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE) {
+          $timezone = DATETIME_STORAGE_TIMEZONE;
+          $text = $this->dateRangeFormatter->formatDateRange($start_timestamp, $end_timestamp, $format, $timezone);
+        }
+        else {
+          $timezone = drupal_get_user_timezone();
+          $text = $this->dateRangeFormatter->formatDateTimeRange($start_timestamp, $end_timestamp, $format, $timezone);
+        }
+
+        $elements[$delta] = [
+          '#plain_text' => $text,
+          '#cache' => [
+            'contexts' => [
+              'timezone',
+            ],
+          ],
+        ];
+      }
+    }
+
+    return $elements;
+  }
+
+}