diff --git a/admin/calendar.php b/admin/calendar.php
index d0b01176..78131e53 100644
--- a/admin/calendar.php
+++ b/admin/calendar.php
@@ -101,6 +101,24 @@ require_once(HESK_PATH . 'inc/show_admin_nav.inc.php');
                 </ul>
             </div>
         </div>
+        <div class="panel panel-default">
+            <div class="panel-heading">
+                <h4><?php echo $hesklang['legend']; ?></h4>
+            </div>
+            <div class="panel-body">
+                <div class="row">
+                    <div class="col-sm-6">
+                        <i class="fa fa-calendar"></i> <?php echo $hesklang['event']; ?>
+                    </div>
+                    <div class="col-sm-6">
+                        <i class="fa fa-ticket"></i> <?php echo $hesklang['ticket']; ?>
+                    </div>
+                    <div class="col-sm-6">
+                        <i class="fa fa-exclamation-triangle"></i> <?php echo $hesklang['overdue_ticket']; ?>
+                    </div>
+                </div>
+            </div>
+        </div>
     </div>
     <div class="col-lg-9">
         <div class="panel panel-default">
diff --git a/js/calendar/mods-for-hesk-calendar-admin-readonly.js b/js/calendar/mods-for-hesk-calendar-admin-readonly.js
index 3d1a65d9..c9cb3cff 100644
--- a/js/calendar/mods-for-hesk-calendar-admin-readonly.js
+++ b/js/calendar/mods-for-hesk-calendar-admin-readonly.js
@@ -110,7 +110,7 @@ function buildEvent(id, dbObject) {
             owner: dbObject.owner,
             priority: dbObject.priority,
             textColor: calculateTextColor(dbObject.categoryColor),
-            fontIconMarkup: '<i class="fa fa-ticket"></i>'
+            fontIconMarkup: getIcon(dbObject)
         };
     }
 
@@ -129,10 +129,21 @@ function buildEvent(id, dbObject) {
         color: dbObject.categoryColor === '' || dbObject.categoryColor === null ? '#fff' : dbObject.categoryColor,
         textColor: calculateTextColor(dbObject.categoryColor),
         reminderValue: dbObject.reminderValue == null ? '' : dbObject.reminderValue,
-        reminderUnits: dbObject.reminderUnits
+        reminderUnits: dbObject.reminderUnits,
+        fontIconMarkup: '<i class="fa fa-calendar"></i>'
     };
 }
 
+function getIcon(dbObject) {
+    var endOfDay = moment(dbObject.startTime).endOf("day");
+
+    if (moment(endOfDay).isBefore(moment())) {
+        return '<i class="fa fa-exclamation-triangle"></i>';
+    }
+
+    return '<i class="fa fa-ticket"></i>';
+}
+
 function calculateTextColor(color) {
     if (color === null || color === '') {
         return 'black';
diff --git a/language/en/text.php b/language/en/text.php
index 6b8b4814..ff8aef38 100644
--- a/language/en/text.php
+++ b/language/en/text.php
@@ -107,6 +107,8 @@ $hesklang['events'] = 'Events';
 $hesklang['add_files'] = '<i class="fa fa-plus"></i> Add File';
 $hesklang['select_all_title_case'] = 'Select All';
 $hesklang['deselect_all_title_case'] = 'Deselect All';
+$hesklang['event'] = 'Event';
+$hesklang['overdue_ticket'] = 'Overdue ticket';
 
 // ADDED OR MODIFIED IN Mods for HESK 2.5.2
 $hesklang['manage_statuses'] = 'Manage Statuses';