diff --git a/scheduler.module b/scheduler.module
index 4ec61bf..d7d5d9c 100644
--- a/scheduler.module
+++ b/scheduler.module
@@ -233,10 +233,14 @@ function scheduler_admin_validate($form, &$form_state) {
   if ($form_state['values']['scheduler_field_type'] == 'date_popup') {
     $format = $form_state['values']['scheduler_date_format'];
     $time_format = date_limit_format($format, array('hour', 'minute', 'second'));
-    $acceptable = date_popup_time_formats();
+    // The Date Popup function date_popup_time_formats() only returns the values
+    // 'H:i:s' and 'h:i:sA' but Scheduler can accept more variations than just
+    // these. Firstly, we add the lowercase 'a' alternative. Secondly timepicker
+    // always requires hours and minutes, but seconds are optional.
+    $acceptable = array('H:i:s', 'h:i:sA', 'h:i:sa', 'H:i', 'h:iA', 'h:ia');
 
     if ($time_format && !in_array($time_format, $acceptable)) {
-      form_set_error('scheduler_date_format', t('The Date Popup module only accepts the following formats: !formats', array('!formats' => implode($acceptable, ', '))));
+      form_set_error('scheduler_date_format', t('When using the Date Popup module, the allowed time formats are: !formats', array('!formats' => implode(', ', $acceptable))));
     }
     if ($time_format == '' && !$form_state['values']['scheduler_allow_date_only']) {
       // When using date popup check that either the main format has a time
@@ -686,9 +690,17 @@ function scheduler_list() {
 function _scheduler_strtotime($str) {
   if ($str && trim($str) != "") {
     $date_format = variable_get('scheduler_date_format', SCHEDULER_DATE_FORMAT);
+    $date_only_format = variable_get('scheduler_date_only_format', SCHEDULER_DATE_ONLY_FORMAT);
 
     if (_scheduler_use_date_popup()) {
-      $date_format = SCHEDULER_DATE_FORMAT;
+      // Date Popup currently returns the value into the $node using its default
+      // format DATE_FORMAT_DATETIME but reduced to the same granularity as the
+      // requested format. Until date issue http://drupal.org/node/1855810 is
+      // resolved we can use the date_popup functions date_format_order() and
+      // date_limit_format() to derive the format of the returned string value.
+      $granularity = date_format_order($date_format);
+      $date_format = date_limit_format(DATE_FORMAT_DATETIME, $granularity);
+      $date_only_format = date_limit_format(DATE_FORMAT_DATETIME, array('day', 'month', 'year'));
     }
     $str = trim(preg_replace('/\s+/', ' ', $str));
     $time = _scheduler_strptime($str, $date_format);
@@ -698,7 +710,6 @@ function _scheduler_strtotime($str) {
     // matches the "date only" date format.
     $time_only_format = variable_get('scheduler_time_only_format', SCHEDULER_TIME_ONLY_FORMAT);
     if ((!$time || $time_only_format == '') && variable_get('scheduler_allow_date_only', FALSE)) {
-      $date_only_format = variable_get('scheduler_date_only_format', SCHEDULER_DATE_ONLY_FORMAT);
       if ($time = _scheduler_strptime($str, $date_only_format)) {
         // A time has been calculated, but also check that there was only a
         // date entered and no extra mal-formed time elements.
diff --git a/scheduler.test b/scheduler.test
index bc518ea..b5f0975 100644
--- a/scheduler.test
+++ b/scheduler.test
@@ -41,7 +41,7 @@ class SchedulerTestCase extends DrupalWebTestCase {
     $this->drupalCreateContentType(array('type' => 'page', 'name' => t('Basic page')));
 
     // Create an administrator user.
-    $this->admin_user = $this->drupalCreateUser(array('access content', 'create page content', 'edit own page content', 'view own unpublished content', 'administer nodes', 'schedule (un)publishing of nodes'));
+    $this->admin_user = $this->drupalCreateUser(array('access content', 'administer scheduler', 'create page content', 'edit own page content', 'view own unpublished content', 'administer nodes', 'schedule (un)publishing of nodes'));
 
     // Add scheduler functionality to the page node type.
     variable_set('scheduler_publish_enable_page', 1);
@@ -549,4 +549,48 @@ class SchedulerTestCase extends DrupalWebTestCase {
       }
     }
   }
+
+  /**
+   * Tests configuration of different date formats with the Date Popup field.
+   */
+  public function testDatePopupFormats() {
+    $this->drupalLogin($this->admin_user);
+
+    // Define some date formats to test.
+    $test_cases = array(
+      // By default we are not using the 'date only' option, so passing only a
+      // date should fail.
+      'Y-m-d' => FALSE,
+      'd-m-Y' => FALSE,
+      'n-j-y' => FALSE,
+
+      // Test a number of supported date formats.
+      'Y-m-d H:i' => TRUE,
+      'd-m-Y h:ia' => TRUE,
+      'n-j-y H:i:s' => TRUE,
+      'y-m-d h:i:sA' => TRUE,
+      'd-m-y h:i:sa' => TRUE,
+
+      // Test a number of date formats with invalid time specifications.
+      'y-m-d G:i' => FALSE,
+      'y-j-n G:i:sa' => FALSE,
+      'Y-m-d g:i:sa' => FALSE,
+      'y-m-d g:i:s' => FALSE,
+      'n-j-y h:i' => FALSE,
+      'd-m-y h:i:s' => FALSE,
+      'd-m-Y H:i:sA' => FALSE,
+      'Y-m-d H:ia' => FALSE,
+    );
+    foreach ($test_cases as $date_format => $expected_result) {
+      $edit = array(
+        'scheduler_date_format' => $date_format,
+        'scheduler_field_type' => 'date_popup',
+      );
+      $this->drupalPost('admin/config/content/scheduler', $edit, t('Save configuration'));
+      $message = format_string('When using date popups the date format %format is @expected', array('%format' => $date_format, '@expected' => $expected_result ? 'allowed' : 'not allowed.'));
+      $assert = $expected_result ? 'assertNoRaw' : 'assertRaw';
+      $this->$assert('Error message', $message);
+    }
+  }
+
 }