diff --git a/date.diff.inc b/date.diff.inc
new file mode 100644
index 0000000..e46d3a1
--- /dev/null
+++ b/date.diff.inc
@@ -0,0 +1,79 @@
+<?php
+
+/**
+ * @file
+ * Provide diff field functions for the Date module.
+ */
+
+/**
+ * Diff field callback for parsing date fields comparative values.
+ */
+function date_field_diff_view($items, $context) {
+  $diff_items = array();
+  $display = $context['display'];
+  $display['settings']['format_type'] = $context['settings']['format_type'];
+  $display['settings']['fromto'] = $context['settings']['fromto'];
+  foreach ($items as $delta => $item) {
+    $date = date_formatter_process('date_default', $context['entity_type'], $context['entity'], $context['field'], $context['instance'], $context['language'], $item, $display);
+    switch ($display['settings']['fromto']) {
+      case 'both':
+        if ($date['value']['formatted'] != $date['value2']['formatted']) {
+          $diff_items[$delta] = t('@from to @to', array(
+            '@from' => $date['value']['formatted'],
+            '@to' => $date['value2']['formatted'],
+          ));
+        }
+        else {
+          $diff_items[$delta] = $date['value']['formatted'];
+        }
+        break;
+
+      case 'value':
+      case 'value2':
+        $diff_items[$delta] = $date[$display['settings']['fromto']]['formatted'];
+        break;
+
+    }
+  }
+  return $diff_items;
+}
+
+/**
+ * Provide default field comparison options.
+ */
+function date_field_diff_default_options($field_type) {
+  return array(
+    'format_type' => 'long',
+    'fromto' => 'both',
+  );
+}
+
+/**
+ * Provide a form for setting the field comparison options.
+ */
+function date_field_diff_options_form($field_type, $settings) {
+  $options_form = array();
+
+  $form['format_type'] = array(
+    '#title' => t('Choose how render dates and times'),
+    '#type' => 'select',
+    '#options' => date_format_type_options(),
+    '#default_value' => $settings['format_type'],
+    '#description' => t('To add or edit options, visit <a href="@date-time-page">Date and time settings</a>.', array('@date-time-page' => url('admin/config/regional/date-time'))),
+    '#weight' => 0,
+  );
+
+  $form['fromto'] = array(
+    '#title' => t('Display'),
+    '#type' => 'select',
+    '#options' => array(
+      'both' => t('Both Start and End dates'),
+      'value' => t('Start date only'),
+      'value2' => t('End date only'),
+    ),
+    '#default_value' => $settings['fromto'],
+    '#weight' => 1,
+  );
+
+  return $options_form;
+}