diff --git a/scheduler.cron.inc b/scheduler.cron.inc
deleted file mode 100644
index ee69e4c..0000000
--- a/scheduler.cron.inc
+++ /dev/null
@@ -1,287 +0,0 @@
-<?php
-
-/**
- * @file
- * Scheduler cron functions.
- *
- * This file is included only when running a crontab job or executing the
- * lightweight cron via the admin interface.
- */
-
-use Drupal\Core\Url;
-use Drupal\node\Entity\Node;
-
-/**
- * Declare exception classes.
- */
-class SchedulerNodeTypeNotEnabledException extends Exception {}
-class SchedulerMissingDateException extends Exception {}
-
-/**
- * Publish scheduled nodes.
- *
- * @return bool
- *   TRUE if any node has been published, FALSE otherwise.
- */
-function _scheduler_publish() {
-  $date_formatter = \Drupal::service('date.formatter');
-  $result = FALSE;
-
-  // If the time now is greater than the time to publish a node, publish it.
-  $query = \Drupal::entityQuery('node')
-    ->condition('publish_on', 0, '>')
-    ->condition('publish_on', REQUEST_TIME, '<=');
-  // @todo Change this query to exclude nodes which are not enabled for
-  // publishing. See https://www.drupal.org/node/2659824
-  $nids = $query->execute();
-
-  $action = 'publish';
-
-  // Allow other modules to add to the list of nodes to be published.
-  $nids = array_unique(array_merge($nids, _scheduler_scheduler_nid_list($action)));
-
-  // Allow other modules to alter the list of nodes to be published.
-  \Drupal::moduleHandler()->alter('scheduler_nid_list', $nids, $action);
-
-  $logger = \Drupal::logger('scheduler');
-  // @todo Use dependency injection for the logger when we have written the new
-  // service for scheduler API. See https://www.drupal.org/node/2651338
-  $nodes = Node::loadMultiple($nids);
-  foreach ($nodes as $nid => $node) {
-    // The API calls could return nodes of types which are not enabled for
-    // scheduled publishing. Do not process these.
-    if (!$node->type->entity->getThirdPartySetting('scheduler', 'publish_enable', SCHEDULER_DEFAULT_PUBLISH_ENABLE)) {
-      throw new SchedulerNodeTypeNotEnabledException(sprintf("Node %d '%s' will not be published because node type '%s' is not enabled for scheduled publishing", $node->id(), $node->getTitle(), node_get_type_label($node)));
-      continue;
-    }
-
-    // Check that other modules allow the action on this node.
-    if (!_scheduler_allow($node, $action)) {
-      continue;
-    }
-
-    // Invoke Scheduler API for modules to react before the node is published.
-    _scheduler_scheduler_api($node, 'pre_' . $action);
-
-    // If an API call has removed the date $node->set('changed', $publish_on)
-    // would fail, so trap this exception here and give a meaningful message.
-    if (empty($node->publish_on->value)) {
-      $field_definitions = \Drupal::entityManager()->getFieldDefinitions('node', $node->getType());
-      $field = (string)$field_definitions['publish_on']->getLabel();
-      throw new SchedulerMissingDateException(sprintf("Node %d '%s' will not be published because field '%s' has no value", $node->id(), $node->getTitle(), $field));
-      continue;
-    }
-
-    // Update timestamps.
-    $publish_on = $node->publish_on->value;
-    $node->set('changed', $publish_on);
-    $old_creation_date = $node->getCreatedTime();
-    if ($node->type->entity->getThirdPartySetting('scheduler', 'publish_touch', SCHEDULER_DEFAULT_PUBLISH_TOUCH)) {
-      $node->setCreatedTime($publish_on);
-    }
-
-    $create_publishing_revision = $node->type->entity->getThirdPartySetting('scheduler', 'publish_revision', SCHEDULER_DEFAULT_PUBLISH_REVISION);
-    if ($create_publishing_revision) {
-      $node->setNewRevision();
-      // Use a core date format to guarantee a time is included.
-      $node->revision_log = t('Node published by Scheduler on @now. Previous creation date was @date.', array(
-        '@now' => $date_formatter->format(REQUEST_TIME, 'short'),
-        '@date' => $date_formatter->format($old_creation_date, 'short'),
-      ));
-    }
-    // Unset publish_on so the node will not get rescheduled by subsequent calls
-    // to $node->save().
-    $node->publish_on->value = NULL;
-
-    // Log the fact that a scheduled publication is about to take place.
-    $view_link = $node->link(t('View node'));
-    $nodetype_url = Url::fromRoute('entity.node_type.edit_form', array('node_type' => $node->getType()));
-    $nodetype_link = \Drupal::l(node_get_type_label($node) . ' ' . t('settings'), $nodetype_url);
-    $logger_variables = array(
-      '@type' => node_get_type_label($node),
-      '%title' => $node->getTitle(),
-      'link' => $nodetype_link . ' ' . $view_link,
-    );
-    $logger->notice('@type: scheduled publishing of %title.', $logger_variables);
-
-    // Use the actions system to publish the node.
-    \Drupal::entityManager()->getStorage('action')->load('node_publish_action')->getPlugin()->execute($node);
-
-    // Invoke the event to tell Rules that Scheduler has published this node.
-    if (\Drupal::moduleHandler()->moduleExists('rules')) {
-      /*
-      TEMP remove call to undefined function rules_invoke_event until converted.
-      @see https://www.drupal.org/node/2651348
-      rules_invoke_event('scheduler_node_has_been_published_event', $node, $publish_on, $node->unpublish_on->value);
-      */
-    }
-
-    // Invoke scheduler API for modules to react after the node is published.
-    _scheduler_scheduler_api($node, $action);
-
-    $result = TRUE;
-  }
-
-  return $result;
-}
-
-/**
- * Unpublish scheduled nodes.
- *
- * @return bool
- *   TRUE is any node has been unpublished, FALSE otherwise.
- */
-function _scheduler_unpublish() {
-  $date_formatter = \Drupal::service('date.formatter');
-  $result = FALSE;
-
-  // If the time is greater than the time to unpublish a node, unpublish it.
-  $query = \Drupal::entityQuery('node')
-    ->condition('unpublish_on', 0, '>')
-    ->condition('unpublish_on', REQUEST_TIME, '<=');
-  // @todo Change this query to exclude nodes which are not enabled for
-  // unpublishing. See https://www.drupal.org/node/2659824
-  $nids = $query->execute();
-
-  $action = 'unpublish';
-
-  // Allow other modules to add to the list of nodes to be unpublished.
-  $nids = array_unique(array_merge($nids, _scheduler_scheduler_nid_list($action)));
-
-  // Allow other modules to alter the list of nodes to be unpublished.
-  \Drupal::moduleHandler()->alter('scheduler_nid_list', $nids, $action);
-
-  $logger = \Drupal::logger('scheduler');
-  // @todo Use dependency injection for the logger when we have written the new
-  // service for scheduler API. See https://www.drupal.org/node/2651338
-  $nodes = Node::loadMultiple($nids);
-  foreach ($nodes as $nid => $node) {
-    // The API calls could return nodes of types which are not enabled for
-    // scheduled unpublishing. Do not process these.
-    if (!$node->type->entity->getThirdPartySetting('scheduler', 'unpublish_enable', SCHEDULER_DEFAULT_UNPUBLISH_ENABLE)) {
-      throw new SchedulerNodeTypeNotEnabledException(sprintf("Node %d '%s' will not be unpublished because node type '%s' is not enabled for scheduled unpublishing", $node->id(), $node->getTitle(), node_get_type_label($node)));
-      continue;
-    }
-
-    // Check that other modules allow the action on this node.
-    if (!_scheduler_allow($node, $action)) {
-      continue;
-    }
-
-    // Do not process the node if it has a publish_on time which is in the past,
-    // as this implies that scheduled publishing has been blocked by one of the
-    // API functions we provide. Hence unpublishing should be halted too.
-    $publish_on = $node->publish_on->value;
-    if (!empty($publish_on) && $publish_on <= REQUEST_TIME) {
-      continue;
-    }
-
-    // Invoke scheduler API for modules to react before the node is unpublished.
-    _scheduler_scheduler_api($node, 'pre_' . $action);
-
-    // If an API call has removed the date $node->set('changed', $unpublish_on)
-    // would fail, so trap this exception here and give a meaningful message.
-    if (empty($node->unpublish_on->value)) {
-      $field_definitions = \Drupal::entityManager()->getFieldDefinitions('node', $node->getType());
-      $field = (string)$field_definitions['unpublish_on']->getLabel();
-      throw new SchedulerMissingDateException(sprintf("Node %d '%s' will not be unpublished because field '%s' has no value", $node->id(), $node->getTitle(), $field));
-      continue;
-    }
-
-    // Update timestamps.
-    $old_change_date = $node->getChangedTime();
-    $unpublish_on = $node->unpublish_on->value;
-    $node->set('changed', $unpublish_on);
-
-    $create_unpublishing_revision = $node->type->entity->getThirdPartySetting('scheduler', 'unpublish_revision', SCHEDULER_DEFAULT_UNPUBLISH_REVISION);
-    if ($create_unpublishing_revision) {
-      $node->setNewRevision();
-      // Use a core date format to guarantee a time is included.
-      $node->revision_log = t('Node unpublished by Scheduler on @now. Previous change date was @date.', array(
-        '@now' => $date_formatter->format(REQUEST_TIME, 'short'),
-        '@date' => $date_formatter->format($old_change_date, 'short'),
-      ));
-    }
-    // Unset unpublish_on so the node will not get rescheduled by subsequent
-    // calls to $node->save(). Save the value for use when calling Rules.
-    $node->unpublish_on->value = NULL;
-
-    // Log the fact that a scheduled unpublication is about to take place.
-    $view_link = $node->link(t('View node'));
-    $nodetype_url = Url::fromRoute('entity.node_type.edit_form', array('node_type' => $node->getType()));
-    $nodetype_link = \Drupal::l(node_get_type_label($node) . ' ' . t('settings'), $nodetype_url);
-    $logger_variables = array(
-      '@type' => node_get_type_label($node),
-      '%title' => $node->getTitle(),
-      'link' => $nodetype_link . ' ' . $view_link,
-    );
-    $logger->notice('@type: scheduled unpublishing of %title.', $logger_variables);
-
-    // Use the actions system to publish the node.
-    \Drupal::entityManager()->getStorage('action')->load('node_unpublish_action')->getPlugin()->execute($node);
-
-    // Invoke event to tell Rules that Scheduler has unpublished this node.
-    if (\Drupal::moduleHandler()->moduleExists('rules')) {
-      /*
-      TEMP remove call to undefined function rules_invoke_event until converted.
-      @see https://www.drupal.org/node/2651348
-      rules_invoke_event('scheduler_node_has_been_unpublished_event', $node, $node->publish_on, $unpublish_on);
-      */
-    }
-
-    // Invoke scheduler API for modules to react after the node is unpublished.
-    _scheduler_scheduler_api($node, $action);
-
-    $result = TRUE;
-  }
-
-  return $result;
-}
-
-/**
- * Gather node IDs for all nodes that need to be $action'ed.
- *
- * @param string $action
- *   The action being performed, either "publish" or "unpublish".
- *
- * @return array
- *   An array of node ids.
- */
-function _scheduler_scheduler_nid_list($action) {
-  $nids = array();
-
-  foreach (\Drupal::moduleHandler()->getImplementations('scheduler_nid_list') as $module) {
-    $function = $module . '_scheduler_nid_list';
-    $nids = array_merge($nids, $function($action));
-  }
-
-  return $nids;
-}
-
-/**
- * Run the lightweight cron.
- *
- * The Scheduler part of the processing performed here is the same as in the
- * normal Drupal cron run. The difference is that only scheduler_cron() is
- * executed, no other modules hook_cron() functions are called.
- *
- * This function is called from the external crontab job via url /scheduler/cron
- * or it can be run interactively from the Scheduler configuration page at
- * /admin/config/content/scheduler/cron.
- */
-function _scheduler_run_cron() {
-  $log = \Drupal::config('scheduler.settings')->get('log');
-  if ($log) {
-    \Drupal::logger('scheduler')->notice('Lightweight cron run activated.');
-  }
-  scheduler_cron();
-  if (ob_get_level() > 0) {
-    $handlers = ob_list_handlers();
-    if (isset($handlers[0]) && $handlers[0] == 'default output handler') {
-      ob_clean();
-    }
-  }
-  if ($log) {
-    \Drupal::logger('scheduler')->notice('Lightweight cron run completed.', array('link' => \Drupal::l(t('settings'), Url::fromRoute('scheduler.cron_form'))));
-  }
-}
diff --git a/scheduler.module b/scheduler.module
index 94b8e5b..f64d3a8 100644
--- a/scheduler.module
+++ b/scheduler.module
@@ -235,40 +235,6 @@ function scheduler_entity_base_field_info(EntityTypeInterface $entity_type) {
 }
 
 /**
- * Checks whether a scheduled action on a node is allowed.
- *
- * This provides a way for other modules to prevent scheduled publishing or
- * unpublishing, by implementing hook_scheduler_allow_publishing() or
- * hook_scheduler_allow_unpublishing().
- *
- * @deprecated Will be moved to a service.
- *
- * @see https://www.drupal.org/node/2651338
- * @see hook_scheduler_allow_publishing()
- * @see hook_scheduler_allow_unpublishing()
- *
- * @param \Drupal\node\NodeInterface $node
- *   The node on which the action is to be performed.
- * @param string $action
- *   The action that needs to be checked. Can be 'publish' or 'unpublish'.
- *
- * @return bool
- *   TRUE if the action is allowed, FALSE if not.
- */
-function _scheduler_allow(NodeInterface $node, $action) {
-  // Default to TRUE.
-  $result = TRUE;
-  // Check that other modules allow the action.
-  $hook = 'scheduler_allow_' . $action . 'ing';
-  foreach (\Drupal::moduleHandler()->getImplementations($hook) as $module) {
-    $function = $module . '_' . $hook;
-    $result &= $function($node);
-  }
-
-  return $result;
-}
-
-/**
  * Implements hook_ENTITY_TYPE_view() for node entities.
  */
 function scheduler_node_view(array &$build, EntityInterface $node, EntityViewDisplayInterface $display, $view_mode) {
@@ -332,7 +298,7 @@ function scheduler_node_presave(EntityInterface $node) {
 
   if ($node->publish_on->value > 0) {
     // Check that other modules allow the action on this node.
-    $publication_allowed = _scheduler_allow($node, 'publish');
+    $publication_allowed = \Drupal::service('scheduler.manager')->isAllowed($node, 'publish');
 
     // Publish the node immediately if the publication date is in the past.
     $publish_immediately = $entity->getThirdPartySetting('scheduler', 'publish_past_date', SCHEDULER_DEFAULT_PUBLISH_PAST_DATE) == 'publish';
@@ -414,17 +380,16 @@ function scheduler_node_update(EntityInterface $node) {
  * Implements hook_cron().
  */
 function scheduler_cron() {
-  // Load the cron functions file.
-  module_load_include('inc', 'scheduler', 'scheduler.cron');
-
   // Use drupal_static so that any function can find out if we are running
   // Scheduler cron. Set the default value to FALSE, then turn on the flag.
   // @see scheduler_cron_is_running()
   $scheduler_cron = &drupal_static(__FUNCTION__, FALSE);
   $scheduler_cron = TRUE;
 
-  _scheduler_publish();
-  _scheduler_unpublish();
+  /** @var \Drupal\scheduler\SchedulerManager $scheduler_manager */
+  $scheduler_manager = \Drupal::service('scheduler.manager');
+  $scheduler_manager->publish();
+  $scheduler_manager->unpublish();
 
   // Reset the static scheduler_cron flag.
   drupal_static_reset(__FUNCTION__);
diff --git a/scheduler.services.yml b/scheduler.services.yml
new file mode 100644
index 0000000..12fb233
--- /dev/null
+++ b/scheduler.services.yml
@@ -0,0 +1,8 @@
+services:
+  scheduler.manager:
+    class: Drupal\scheduler\SchedulerManager
+    arguments: ['@date.formatter', '@logger.channel.scheduler', '@module_handler', '@entity.manager', '@config.factory' ]
+  logger.channel.scheduler:
+    class: Drupal\Core\Logger\LoggerChannel
+    factory: logger.factory:get
+    arguments: ['scheduler']
diff --git a/src/Controller/LightweightCronController.php b/src/Controller/LightweightCronController.php
index 05612ca..b845f66 100644
--- a/src/Controller/LightweightCronController.php
+++ b/src/Controller/LightweightCronController.php
@@ -25,9 +25,7 @@ class LightweightCronController extends ControllerBase {
    *   RedirectResponse.
    */
   public function index() {
-    module_load_include('inc', 'scheduler', 'scheduler.cron');
-
-    _scheduler_run_cron();
+    \Drupal::service('scheduler.manager')->runCron();
 
     return new Response('', 204);
   }
diff --git a/src/Exception/SchedulerMissingDateException.php b/src/Exception/SchedulerMissingDateException.php
new file mode 100644
index 0000000..fea1e45
--- /dev/null
+++ b/src/Exception/SchedulerMissingDateException.php
@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\scheduler\Exception\SchedulerMissingDateException.
+ */
+
+namespace Drupal\scheduler\Exception;
+
+/**
+ * Thrown by SchedulerManager.
+ *
+ * @see SchedulerManager::publish()
+ */
+class SchedulerMissingDateException extends \Exception { }
diff --git a/src/Exception/SchedulerNodeTypeNotEnabledException.php b/src/Exception/SchedulerNodeTypeNotEnabledException.php
new file mode 100644
index 0000000..a6eb1fe
--- /dev/null
+++ b/src/Exception/SchedulerNodeTypeNotEnabledException.php
@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\scheduler\Exception\SchedulerNodeTypeNotEnabledException.
+ */
+
+namespace Drupal\scheduler\Exception;
+
+/**
+ * Thrown by SchedulerManager.
+ *
+ * @see SchedulerManager::publish()
+ */
+class SchedulerNodeTypeNotEnabledException extends \Exception { }
diff --git a/src/Form/SchedulerCronForm.php b/src/Form/SchedulerCronForm.php
index 3b48c7d..a3107e0 100644
--- a/src/Form/SchedulerCronForm.php
+++ b/src/Form/SchedulerCronForm.php
@@ -143,8 +143,7 @@ class SchedulerCronForm extends ConfigFormBase {
    *   The current state of the form.
    */
   public function runLightweightCron(array &$form, FormStateInterface $form_state) {
-    module_load_include('inc', 'scheduler', 'scheduler.cron');
-    _scheduler_run_cron();
+    \Drupal::service('scheduler.manager')->runCron();
 
     if ($this->moduleHandler->moduleExists('dblog')) {
       $url = Url::fromRoute('dblog.overview')->toString();
diff --git a/src/SchedulerManager.php b/src/SchedulerManager.php
new file mode 100644
index 0000000..3b12244
--- /dev/null
+++ b/src/SchedulerManager.php
@@ -0,0 +1,370 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\scheduler\SchedulerManager.
+ */
+
+namespace Drupal\scheduler;
+
+use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Datetime\DateFormatter;
+use Drupal\Core\Entity\EntityManager;
+use Drupal\Core\Url;
+use Drupal\Core\Extension\ModuleHandler;
+use Drupal\node\Entity\Node;
+use Drupal\node\NodeInterface;
+use Drupal\scheduler\Exception\SchedulerMissingDateException;
+use Drupal\scheduler\Exception\SchedulerNodeTypeNotEnabledException;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Defines a scheduler manager.
+ */
+class SchedulerManager {
+
+  /**
+   * Date formatter service object.
+   *
+   * @var \Drupal\Core\Datetime\DateFormatter
+   */
+  protected $dateFormatter;
+
+  /**
+   * Scheduler Logger service object.
+   *
+   * @var \Psr\Log\LoggerInterface
+   */
+  protected $logger;
+
+  /**
+   * Module handler service object.
+   *
+   * @var  \Drupal\Core\Extension\ModuleHandler
+   */
+  protected $moduleHandler;
+
+  /**
+   * Entity Manager service object.
+   *
+   * @var  \Drupal\Core\Entity\EntityManager
+   */
+  protected $entityManager;
+
+  /**
+   * Config Factory service object.
+   *
+   * @var \Drupal\Core\Config\ConfigFactory
+   */
+  protected $configFactory;
+
+  /**
+   * Constructs a SchedulerManager object.
+   */
+  public function __construct(DateFormatter $dateFormatter, LoggerInterface $logger, ModuleHandler $moduleHandler, EntityManager $entityManager, ConfigFactory $configFactory) {
+    $this->dateFormatter = $dateFormatter;
+    $this->logger = $logger;
+    $this->moduleHandler = $moduleHandler;
+    $this->entityManager = $entityManager;
+    $this->configFactory = $configFactory;
+  }
+
+  /**
+   * Publish scheduled nodes.
+   *
+   * @return bool
+   *   TRUE if any node has been published, FALSE otherwise.
+   *
+   * @throws \Drupal\scheduler\Plugin\Exception\SchedulerMissingDateException
+   * @throws \Drupal\scheduler\Plugin\Exception\SchedulerNodeTypeNotEnabledException
+   */
+  public function publish() {
+    $result = FALSE;
+
+    // If the time now is greater than the time to publish a node, publish it.
+    $query = \Drupal::entityQuery('node')
+      ->condition('publish_on', 0, '>')
+      ->condition('publish_on', REQUEST_TIME, '<=');
+    // @todo Change this query to exclude nodes which are not enabled for
+    // publishing. See https://www.drupal.org/node/2659824
+    $nids = $query->execute();
+
+    $action = 'publish';
+
+    // Allow other modules to add to the list of nodes to be published.
+    $nids = array_unique(array_merge($nids, $this->nidList($action)));
+
+    // Allow other modules to alter the list of nodes to be published.
+    $this->moduleHandler->alter('scheduler_nid_list', $nids, $action);
+
+    $nodes = Node::loadMultiple($nids);
+    foreach ($nodes as $nid => $node) {
+      // The API calls could return nodes of types which are not enabled for
+      // scheduled publishing. Do not process these.
+      if (!$node->type->entity->getThirdPartySetting('scheduler', 'publish_enable', SCHEDULER_DEFAULT_PUBLISH_ENABLE)) {
+        throw new SchedulerNodeTypeNotEnabledException(sprintf("Node %d '%s' will not be published because node type '%s' is not enabled for scheduled publishing", $node->id(), $node->getTitle(), node_get_type_label($node)));
+        continue;
+      }
+
+      // Check that other modules allow the action on this node.
+      if (!$this->isAllowed($node, $action)) {
+        continue;
+      }
+
+      // Invoke Scheduler API for modules to react before the node is published.
+      _scheduler_scheduler_api($node, 'pre_' . $action);
+
+      // If an API call has removed the date $node->set('changed', $publish_on)
+      // would fail, so trap this exception here and give a meaningful message.
+      if (empty($node->publish_on->value)) {
+        $field_definitions = $this->entityManager->getFieldDefinitions('node', $node->getType());
+        $field = (string)$field_definitions['publish_on']->getLabel();
+        throw new SchedulerMissingDateException(sprintf("Node %d '%s' will not be published because field '%s' has no value", $node->id(), $node->getTitle(), $field));
+        continue;
+      }
+
+      // Update timestamps.
+      $publish_on = $node->publish_on->value;
+      $node->set('changed', $publish_on);
+      $old_creation_date = $node->getCreatedTime();
+      if ($node->type->entity->getThirdPartySetting('scheduler', 'publish_touch', SCHEDULER_DEFAULT_PUBLISH_TOUCH)) {
+        $node->setCreatedTime($publish_on);
+      }
+
+      $create_publishing_revision = $node->type->entity->getThirdPartySetting('scheduler', 'publish_revision', SCHEDULER_DEFAULT_PUBLISH_REVISION);
+      if ($create_publishing_revision) {
+        $node->setNewRevision();
+        // Use a core date format to guarantee a time is included.
+        $node->revision_log = t('Node published by Scheduler on @now. Previous creation date was @date.', array(
+          '@now' => $this->dateFormatter->format(REQUEST_TIME, 'short'),
+          '@date' => $this->dateFormatter->format($old_creation_date, 'short'),
+        ));
+      }
+      // Unset publish_on so the node will not get rescheduled by subsequent calls
+      // to $node->save().
+      $node->publish_on->value = NULL;
+
+      // Log the fact that a scheduled publication is about to take place.
+      $view_link = $node->link(t('View node'));
+      $nodetype_url = Url::fromRoute('entity.node_type.edit_form', array('node_type' => $node->getType()));
+      $nodetype_link = \Drupal::l(node_get_type_label($node) . ' ' . t('settings'), $nodetype_url);
+      $logger_variables = array(
+        '@type' => node_get_type_label($node),
+        '%title' => $node->getTitle(),
+        'link' => $nodetype_link . ' ' . $view_link,
+      );
+      $this->logger->notice('@type: scheduled publishing of %title.', $logger_variables);
+
+      // Use the actions system to publish the node.
+      $this->entityManager->getStorage('action')->load('node_publish_action')->getPlugin()->execute($node);
+
+      // Invoke the event to tell Rules that Scheduler has published this node.
+      if ($this->moduleHandler->moduleExists('rules')) {
+        /*
+        TEMP remove call to undefined function rules_invoke_event until converted.
+        @see https://www.drupal.org/node/2651348
+        rules_invoke_event('scheduler_node_has_been_published_event', $node, $publish_on, $node->unpublish_on->value);
+        */
+      }
+
+      // Invoke scheduler API for modules to react after the node is published.
+      _scheduler_scheduler_api($node, $action);
+
+      $result = TRUE;
+    }
+
+    return $result;
+  }
+
+  /**
+   * Unpublish scheduled nodes.
+   *
+   * @return bool
+   *   TRUE if any node has been unpublished, FALSE otherwise.
+   *
+   * @throws \Drupal\scheduler\Plugin\Exception\SchedulerMissingDateException
+   * @throws \Drupal\scheduler\Plugin\Exception\SchedulerNodeTypeNotEnabledException
+   */
+  public function unpublish() {
+    $result = FALSE;
+
+    // If the time is greater than the time to unpublish a node, unpublish it.
+    $query = \Drupal::entityQuery('node')
+      ->condition('unpublish_on', 0, '>')
+      ->condition('unpublish_on', REQUEST_TIME, '<=');
+    // @todo Change this query to exclude nodes which are not enabled for
+    // unpublishing. See https://www.drupal.org/node/2659824
+    $nids = $query->execute();
+
+    $action = 'unpublish';
+
+    // Allow other modules to add to the list of nodes to be unpublished.
+    $nids = array_unique(array_merge($nids, $this->nidList($action)));
+
+    // Allow other modules to alter the list of nodes to be unpublished.
+    $this->moduleHandler->alter('scheduler_nid_list', $nids, $action);
+
+    $nodes = Node::loadMultiple($nids);
+    foreach ($nodes as $nid => $node) {
+      // The API calls could return nodes of types which are not enabled for
+      // scheduled unpublishing. Do not process these.
+      if (!$node->type->entity->getThirdPartySetting('scheduler', 'unpublish_enable', SCHEDULER_DEFAULT_UNPUBLISH_ENABLE)) {
+        throw new SchedulerNodeTypeNotEnabledException(sprintf("Node %d '%s' will not be unpublished because node type '%s' is not enabled for scheduled unpublishing", $node->id(), $node->getTitle(), node_get_type_label($node)));
+        continue;
+      }
+
+      // Check that other modules allow the action on this node.
+      if (!$this->isAllowed($node, $action)) {
+        continue;
+      }
+
+      // Do not process the node if it has a publish_on time which is in the past,
+      // as this implies that scheduled publishing has been blocked by one of the
+      // API functions we provide. Hence unpublishing should be halted too.
+      $publish_on = $node->publish_on->value;
+      if (!empty($publish_on) && $publish_on <= REQUEST_TIME) {
+        continue;
+      }
+
+      // Invoke scheduler API for modules to react before the node is unpublished.
+      _scheduler_scheduler_api($node, 'pre_' . $action);
+
+      // If an API call has removed the date $node->set('changed', $unpublish_on)
+      // would fail, so trap this exception here and give a meaningful message.
+      if (empty($node->unpublish_on->value)) {
+        $field_definitions = $this->entityManager->getFieldDefinitions('node', $node->getType());
+        $field = (string)$field_definitions['unpublish_on']->getLabel();
+        throw new SchedulerMissingDateException(sprintf("Node %d '%s' will not be unpublished because field '%s' has no value", $node->id(), $node->getTitle(), $field));
+        continue;
+      }
+
+      // Update timestamps.
+      $old_change_date = $node->getChangedTime();
+      $unpublish_on = $node->unpublish_on->value;
+      $node->set('changed', $unpublish_on);
+
+      $create_unpublishing_revision = $node->type->entity->getThirdPartySetting('scheduler', 'unpublish_revision', SCHEDULER_DEFAULT_UNPUBLISH_REVISION);
+      if ($create_unpublishing_revision) {
+        $node->setNewRevision();
+        // Use a core date format to guarantee a time is included.
+        $node->revision_log = t('Node unpublished by Scheduler on @now. Previous change date was @date.', array(
+          '@now' => $this->dateFormatter->format(REQUEST_TIME, 'short'),
+          '@date' => $this->dateFormatter->format($old_change_date, 'short'),
+        ));
+      }
+      // Unset unpublish_on so the node will not get rescheduled by subsequent
+      // calls to $node->save(). Save the value for use when calling Rules.
+      $node->unpublish_on->value = NULL;
+
+      // Log the fact that a scheduled unpublication is about to take place.
+      $view_link = $node->link(t('View node'));
+      $nodetype_url = Url::fromRoute('entity.node_type.edit_form', array('node_type' => $node->getType()));
+      $nodetype_link = \Drupal::l(node_get_type_label($node) . ' ' . t('settings'), $nodetype_url);
+      $logger_variables = array(
+        '@type' => node_get_type_label($node),
+        '%title' => $node->getTitle(),
+        'link' => $nodetype_link . ' ' . $view_link,
+      );
+      $this->logger->notice('@type: scheduled unpublishing of %title.', $logger_variables);
+
+      // Use the actions system to publish the node.
+      $this->entityManager->getStorage('action')->load('node_unpublish_action')->getPlugin()->execute($node);
+
+      // Invoke event to tell Rules that Scheduler has unpublished this node.
+      if ($this->moduleHandler->moduleExists('rules')) {
+        /*
+        TEMP remove call to undefined function rules_invoke_event until converted.
+        @see https://www.drupal.org/node/2651348
+        rules_invoke_event('scheduler_node_has_been_unpublished_event', $node, $node->publish_on, $unpublish_on);
+        */
+      }
+
+      // Invoke scheduler API for modules to react after the node is unpublished.
+      _scheduler_scheduler_api($node, $action);
+
+      $result = TRUE;
+    }
+
+    return $result;
+  }
+
+  /**
+   * Checks whether a scheduled action on a node is allowed.
+   *
+   * This provides a way for other modules to prevent scheduled publishing or
+   * unpublishing, by implementing hook_scheduler_allow_publishing() or
+   * hook_scheduler_allow_unpublishing().
+   *
+   * @see hook_scheduler_allow_publishing()
+   * @see hook_scheduler_allow_unpublishing()
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   The node on which the action is to be performed.
+   * @param string $action
+   *   The action that needs to be checked. Can be 'publish' or 'unpublish'.
+   *
+   * @return bool
+   *   TRUE if the action is allowed, FALSE if not.
+   */
+  public function isAllowed(NodeInterface $node, $action) {
+    // Default to TRUE.
+    $result = TRUE;
+    // Check that other modules allow the action.
+    $hook = 'scheduler_allow_' . $action . 'ing';
+    foreach ($this->moduleHandler->getImplementations($hook) as $module) {
+      $function = $module . '_' . $hook;
+      $result &= $function($node);
+    }
+
+    return $result;
+  }
+
+  /**
+   * Gather node IDs for all nodes that need to be $action'ed.
+   *
+   * @param string $action
+   *   The action being performed, either "publish" or "unpublish".
+   *
+   * @return array
+   *   An array of node ids.
+   */
+  public function nidList($action) {
+    $nids = array();
+
+    foreach ($this->moduleHandler->getImplementations('scheduler_nid_list') as $module) {
+      $function = $module . '_scheduler_nid_list';
+      $nids = array_merge($nids, $function($action));
+    }
+
+    return $nids;
+  }
+
+  /**
+   * Run the lightweight cron.
+   *
+   * The Scheduler part of the processing performed here is the same as in the
+   * normal Drupal cron run. The difference is that only scheduler_cron() is
+   * executed, no other modules hook_cron() functions are called.
+   *
+   * This function is called from the external crontab job via url /scheduler/cron
+   * or it can be run interactively from the Scheduler configuration page at
+   * /admin/config/content/scheduler/cron.
+   */
+  public function runCron() {
+    $log = $this->configFactory->get('scheduler.settings')->get('log');
+    if ($log) {
+      $this->logger->notice('Lightweight cron run activated.');
+    }
+    scheduler_cron();
+    if (ob_get_level() > 0) {
+      $handlers = ob_list_handlers();
+      if (isset($handlers[0]) && $handlers[0] == 'default output handler') {
+        ob_clean();
+      }
+    }
+    if ($log) {
+      $this->logger->notice('Lightweight cron run completed.', array('link' => \Drupal::l(t('settings'), Url::fromRoute('scheduler.cron_form'))));
+    }
+  }
+
+}