diff --git a/scheduler.module b/scheduler.module
index 67b0050..646b0d6 100644
--- a/scheduler.module
+++ b/scheduler.module
@@ -472,10 +472,18 @@ function scheduler_form_alter(&$form, $form_state) {
         $defaults->unpublish_on = _scheduler_strtotime($defaults->unpublish_on);
       }
 
-      $publishing_required = variable_get('scheduler_publish_required_' . $form['type']['#value'], 0) == 1 && $node->status == 0;
-      $unpublishing_required = variable_get('scheduler_unpublish_required_' . $form['type']['#value'], 0) == 1 && $node->status == 1;
-      $use_vertical_tabs = variable_get('scheduler_use_vertical_tabs_' . $form['type']['#value'], 1);
+      // A publish_on date is required if the content type option is set and the
+      // node is being created or it currently has a scheduled publishing date.
+      $publishing_required = variable_get('scheduler_publish_required_' . $form['type']['#value'], 0) == 1
+        && (empty($node->nid) || ($node->status == 0 && !empty($node->publish_on)));
+
+      // An unpublish_on date is required if the content type option is set and
+      // the node is being created or the current status is published or the
+      // node is scheduled to be published.
+      $unpublishing_required = variable_get('scheduler_unpublish_required_' . $form['type']['#value'], 0) == 1
+        && (empty($node->nid) || $node->status == 1 || !empty($node->publish_on));
 
+      $use_vertical_tabs = variable_get('scheduler_use_vertical_tabs_' . $form['type']['#value'], 1);
       $fieldset_extended = (
         (isset($defaults->publish_on) && $defaults->publish_on != 0)
         || (isset($defaults->unpublish_on) && $defaults->unpublish_on != 0)
diff --git a/scheduler.test b/scheduler.test
index 5e76f4e..9504a38 100644
--- a/scheduler.test
+++ b/scheduler.test
@@ -362,4 +362,194 @@ class SchedulerTestCase extends DrupalWebTestCase {
     $this->assertFieldByName($unpublish_time_field, date($time_format, strtotime('tomorrow +1 day', REQUEST_TIME) + 23400), 'The default time offset has been added to the date field when scheduling content for unpublication.');
   }
 
+  /**
+   * Tests creating and editing nodes with required scheduling enabled.
+   */
+  function testRequiredScheduling() {
+    $this->drupalLogin($this->admin_user);
+
+    // Define test scenarios with expected results.
+    $test_cases = array(
+      // The 1-10 numbering used below matches the test cases described in
+      // http://drupal.org/node/1198788#comment-7816119
+
+      // A. Test scenarios that require scheduled publishing.
+
+      // When creating a new unpublished node it is required to enter a
+      // publication date.
+      array(
+        'id' => 1,
+        'required' => 'publish',
+        'operation' => 'add',
+        'status' => 0,
+        'expected' => 'required',
+        'message' => 'When scheduled publishing is required and a new unpublished node is created, entering a date in the publish on field is required.',
+      ),
+
+      // When creating a new published node it is required to enter a
+      // publication date. The node will be unpublished on form submit.
+      array(
+        'id' => 2,
+        'required' => 'publish',
+        'operation' => 'add',
+        'status' => 1,
+        'expected' => 'required',
+        'message' => 'When scheduled publishing is required and a new published node is created, entering a date in the publish on field is required.',
+      ),
+
+      // When editing a published node it is not needed to enter a publication
+      // date since the node is already published.
+      array(
+        'id' => 3,
+        'required' => 'publish',
+        'operation' => 'edit',
+        'scheduled' => 0,
+        'status' => 1,
+        'expected' => 'not required',
+        'message' => 'When scheduled publishing is required and an existing published, unscheduled node is edited, entering a date in the publish on field is not required.',
+      ),
+
+      // When editing an unpublished node that is scheduled for publication it
+      // is required to enter a publication date.
+      array(
+        'id' => 4,
+        'required' => 'publish',
+        'operation' => 'edit',
+        'scheduled' => 1,
+        'status' => 0,
+        'expected' => 'required',
+        'message' => 'When scheduled publishing is required and an existing unpublished, scheduled node is edited, entering a date in the publish on field is required.',
+      ),
+
+      // When editing an unpublished node that is not scheduled for publication
+      // it is not required to enter a publication date since this means that
+      // the node has already gone through a publication > unpublication cycle.
+      array(
+        'id' => 5,
+        'required' => 'publish',
+        'operation' => 'edit',
+        'scheduled' => 0,
+        'status' => 0,
+        'expected' => 'not required',
+        'message' => 'When scheduled publishing is required and an existing unpublished, unscheduled node is edited, entering a date in the publish on field is not required.',
+      ),
+
+      // B. Test scenarios that require scheduled unpublishing.
+
+      // When creating a new unpublished node it is required to enter an
+      // unpublication date since it is to be expected that the node will be
+      // published at some point and should subsequently be unpublished.
+      array(
+        'id' => 6,
+        'required' => 'unpublish',
+        'operation' => 'add',
+        'status' => 0,
+        'expected' => 'required',
+        'message' => 'When scheduled unpublishing is required and a new unpublished node is created, entering a date in the unpublish on field is required.',
+      ),
+
+      // When creating a new published node it is required to enter an
+      // unpublication date.
+      array(
+        'id' => 7,
+        'required' => 'unpublish',
+        'operation' => 'add',
+        'status' => 1,
+        'expected' => 'required',
+        'message' => 'When scheduled unpublishing is required and a new published node is created, entering a date in the unpublish on field is required.',
+      ),
+
+      // When editing a published node it is required to enter an unpublication
+      // date.
+      array(
+        'id' => 8,
+        'required' => 'unpublish',
+        'operation' => 'edit',
+        'scheduled' => 0,
+        'status' => 1,
+        'expected' => 'required',
+        'message' => 'When scheduled unpublishing is required and an existing published, unscheduled node is edited, entering a date in the unpublish on field is required.',
+      ),
+
+      // When editing an unpublished node that is scheduled for publication it
+      // it is required to enter an unpublication date.
+      array(
+        'id' => 9,
+        'required' => 'unpublish',
+        'operation' => 'edit',
+        'scheduled' => 1,
+        'status' => 0,
+        'expected' => 'required',
+        'message' => 'When scheduled unpublishing is required and an existing unpublished, scheduled node is edited, entering a date in the unpublish on field is required.',
+      ),
+
+      // When editing an unpublished node that is not scheduled for publication
+      // it is not required to enter an unpublication date since this means that
+      // the node has already gone through a publication - unpublication cycle.
+      array(
+        'id' => 10,
+        'required' => 'unpublish',
+        'operation' => 'edit',
+        'scheduled' => 0,
+        'status' => 0,
+        'expected' => 'not required',
+        'message' => 'When scheduled unpublishing is required and an existing unpublished, unscheduled node is edited, entering a date in the unpublish on field is not required.',
+      ),
+    );
+
+    foreach ($test_cases as $test_case) {
+      // Enable required (un)publishing as stipulated by the test case.
+      variable_set('scheduler_publish_required_page', $test_case['required'] == 'publish');
+      variable_set('scheduler_unpublish_required_page', $test_case['required'] == 'unpublish');
+
+      // Set the default node status, used when creating a new node.
+      $node_options_page = !empty($test_case['status']) ? array('status') : array();
+      variable_set('node_options_page', $node_options_page);
+
+      // To assist viewing and analysing the generated test result pages create
+      // a text string showing all the test case parameters.
+      $title_data = array();
+      foreach ($test_case as $key => $value) {
+        if ($key != 'message') {
+          $title_data[] = $key . ' = ' . $value;
+        }
+      }
+      $title = implode(', ', $title_data);
+
+      // If the test case requires editing a node, we need to create one first.
+      if ($test_case['operation'] == 'edit') {
+        $options = array(
+          'title' => $title,
+          'type' => 'page',
+          'status' => $test_case['status'],
+          'publish_on' => !empty($test_case['scheduled']) ? strtotime('+ 1 day') : 0,
+        );
+        $node = $this->drupalCreateNode($options);
+      }
+
+      // Make sure the publication date fields are empty so we can check if they
+      // throw form validation errors when they are required.
+      $edit = array(
+        'title' => $title,
+        'publish_on' => '',
+        'unpublish_on' => '',
+      );
+      $path = $test_case['operation'] == 'add' ? 'node/add/page' : 'node/' . $node->nid . '/edit';
+      $this->drupalPost($path, $edit, t('Save'));
+
+      // Check for the expected result.
+      switch ($test_case['expected']) {
+        case 'required':
+          $string = t('!name field is required.', array('!name' => ucfirst($test_case['required']) . ' on'));
+          $this->assertRaw($string, $test_case['id'] . '. ' . $test_case['message']);
+          break;
+
+        case 'not required':
+          $string = '@type %title has been ' . ($test_case['operation'] == 'add' ? 'created' : 'updated') . '.';
+          $args = array('@type' => 'Basic page', '%title' => $title);
+          $this->assertRaw(t($string, $args), $test_case['id'] . '. ' . $test_case['message']);
+          break;
+      }
+    }
+  }
 }