commit 64bbef62e1bb7114b70cf24e124b0a31fe9b865b
Author: Darrick Servis <darrick@davismedia.org>
Date:   Mon Feb 1 21:20:17 2016 -0700

    2161337-50.patch

diff --git a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
index a1637a9..6dad92e 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
@@ -60,7 +60,7 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
         $output = $this->formatDate($date);
       }
 
-      if ($item->date2) {
+      if ($item->date2 && $item->date != $item->date2) {
         /** @var \Drupal\Core\Datetime\DrupalDateTime $date */
         $date2 = $item->date2;
         // Create the ISO date in Universal Time.
@@ -73,6 +73,13 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
         $this->setTimeZone($date2);
 
         $output2 = $this->formatDate($date2);
+
+        // Check if start day == end day.
+        $length = strspn($output2, $output);
+        if ($length) {
+
+          $output2 = substr($output2, $length - 1);
+        }
       }
 
       // Display the date using theme datetime.
@@ -91,7 +98,7 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
       ];
 
       // Append on the end date.
-      if ($this->getFieldSetting('enddate_get')) {
+      if ($this->getFieldSetting('enddate_get') && !empty($output2)) {
         $elements[$delta][] = [
           '#markup' => $this->t(' to '),
         ];
diff --git a/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeFieldItemList.php b/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeFieldItemList.php
index b0bc7ba..5b4470a 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeFieldItemList.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldType/DateTimeFieldItemList.php
@@ -29,6 +29,11 @@ class DateTimeFieldItemList extends FieldItemList {
   const DEFAULT_VALUE_CUSTOM = 'relative';
 
   /**
+   * Defines the default value as relative.
+   */
+  const DEFAULT_VALUE_SAME = 'same';
+
+  /**
    * {@inheritdoc}
    */
   public function defaultValuesForm(array &$form, FormStateInterface $form_state) {
@@ -56,11 +61,44 @@ public function defaultValuesForm(array &$form, FormStateInterface $form_state)
           '#states' => array(
             'visible' => array(
               ':input[id="edit-default-value-input-default-date-type"]' => array('value' => static::DEFAULT_VALUE_CUSTOM),
-            )
-          )
-        )
+            ),
+          ),
+        ),
       );
 
+      if ($this->getFieldDefinition()->getSetting('enddate_get')) {
+        $element += array(
+          'default_date_type2' => array(
+            '#type' => 'select',
+            '#title' => t('Default end date'),
+            '#description' => t('Set a default value for this end date.'),
+            '#default_value' => isset($default_value[0]['default_date_type2']) ? $default_value[0]['default_date_type2'] : '',
+            '#options' => array(
+              static::DEFAULT_VALUE_SAME => t('Same as Default date'),
+              static::DEFAULT_VALUE_NOW => t('Current date'),
+              static::DEFAULT_VALUE_CUSTOM => t('Relative date'),
+            ),
+            '#empty_value' => '',
+            '#states' => array(
+              'visible' => array(
+                ':input[id="edit-default-value-input-default-date-type"]' => array('filled' => TRUE),
+              ),
+            ),
+          ),
+          'default_date2' => array(
+            '#type' => 'textfield',
+            '#title' => t('Relative default end value'),
+            '#description' => t("Describe a time by reference to the current day, like '+90 days' (90 days from the day the field is created) or '+1 Saturday' (the next Saturday). See <a href=\"@url\">@strtotime</a> for more details.", array('@strtotime' => 'strtotime', '@url' => 'http://www.php.net/manual/en/function.strtotime.php')),
+            '#default_value' => (isset($default_value[0]['default_date_type2']) && $default_value[0]['default_date_type2'] == static::DEFAULT_VALUE_CUSTOM) ? $default_value[0]['default_date2'] : '',
+            '#states' => array(
+              'visible' => array(
+                ':input[id="edit-default-value-input-default-date-type2"]' => array('value' => static::DEFAULT_VALUE_CUSTOM),
+              ),
+            ),
+          ),
+        );
+      }
+
       return $element;
     }
   }
@@ -75,6 +113,13 @@ public function defaultValuesFormValidate(array $element, array &$form, FormStat
         $form_state->setErrorByName('default_value_input][default_date', t('The relative date value entered is invalid.'));
       }
     }
+
+    if ($form_state->getValue(['default_value_input', 'default_date_type2']) == static::DEFAULT_VALUE_CUSTOM) {
+      $is_strtotime = @strtotime($form_state->getValue(array('default_value_input', 'default_date2')));
+      if (!$is_strtotime) {
+        $form_state->setErrorByName('default_value_input][default_date2', t('The relative date value entered is invalid.'));
+      }
+    }
   }
 
   /**
@@ -82,9 +127,18 @@ public function defaultValuesFormValidate(array $element, array &$form, FormStat
    */
   public function defaultValuesFormSubmit(array $element, array &$form, FormStateInterface $form_state) {
     if ($form_state->getValue(array('default_value_input', 'default_date_type'))) {
+      // Set the start date default to now.
       if ($form_state->getValue(array('default_value_input', 'default_date_type')) == static::DEFAULT_VALUE_NOW) {
         $form_state->setValueForElement($element['default_date'], static::DEFAULT_VALUE_NOW);
       }
+      // Set the end date default to now.
+      if ($form_state->getValue(array('default_value_input', 'default_date_type2')) == static::DEFAULT_VALUE_NOW) {
+        $form_state->setValueForElement($element['default_date2'], static::DEFAULT_VALUE_NOW);
+      }
+      // Set the end date default to same default as start date.
+      if ($form_state->getValue(array('default_value_input', 'default_date_type2')) == static::DEFAULT_VALUE_SAME) {
+        $form_state->setValueForElement($element['default_date2'], $form_state->getValue(array('default_value_input', 'default_date')));
+      }
       return array($form_state->getValue('default_value_input'));
     }
     return array();
@@ -95,12 +149,13 @@ public function defaultValuesFormSubmit(array $element, array &$form, FormStateI
    */
   public static function processDefaultValue($default_value, FieldableEntityInterface $entity, FieldDefinitionInterface $definition) {
     $default_value = parent::processDefaultValue($default_value, $entity, $definition);
+    $default_date_type2 = $default_value[0]['default_date_type2'];
 
     if (isset($default_value[0]['default_date_type'])) {
       // A default value should be in the format and timezone used for date
       // storage.
       $date = new DrupalDateTime($default_value[0]['default_date'], DATETIME_STORAGE_TIMEZONE);
-      $storage_format = $definition->getSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE ? DATETIME_DATE_STORAGE_FORMAT: DATETIME_DATETIME_STORAGE_FORMAT;
+      $storage_format = $definition->getSetting('datetime_type') == DateTimeItem::DATETIME_TYPE_DATE ? DATETIME_DATE_STORAGE_FORMAT : DATETIME_DATETIME_STORAGE_FORMAT;
       $value = $date->format($storage_format);
       // We only provide a default value for the first item, as do all fields.
       // Otherwise, there is no way to clear out unwanted values on multiple value
@@ -109,12 +164,24 @@ public static function processDefaultValue($default_value, FieldableEntityInterf
         array(
           'value' => $value,
           'date' => $date,
-        )
+        ),
       );
-      if ($definition->getSetting('enddate_get')) {
-        $default_value[0]['value2'] = $value;
-        $default_value[0]['date2'] = $date;
       }
+
+    // Repeat for end date.
+    if ($definition->getSetting('enddate_get') && !empty($default_date_type2)) {
+      // A default value should be in the format and timezone used for date
+      // storage.
+      $date = new DrupalDateTime($default_value[0]['default_date2'], DATETIME_STORAGE_TIMEZONE);
+      $storage_format = $definition->getSetting('datetime_type2') == DateTimeItem::DATETIME_TYPE_DATE ? DATETIME_DATE_STORAGE_FORMAT : DATETIME_DATETIME_STORAGE_FORMAT;
+      $value = $date->format($storage_format);
+      // We only provide a default value for the first item, as do all fields.
+      // Otherwise, there is no way to clear out unwanted values on multiple value
+      // fields.
+      $default_value[0] += array(
+        'value2' => $value,
+        'date2' => $date,
+      );
     }
     return $default_value;
   }