diff --git a/mod/chat/lib.php b/mod/chat/lib.php
index e36a70acc82..dd7726f7369 100644
--- a/mod/chat/lib.php
+++ b/mod/chat/lib.php
@@ -113,20 +113,21 @@ function chat_add_instance($chat) {
 
     $returnid = $DB->insert_record("chat", $chat);
 
-    $event = new stdClass();
-    $event->name        = $chat->name;
-    $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
-    $event->courseid    = $chat->course;
-    $event->groupid     = 0;
-    $event->userid      = 0;
-    $event->modulename  = 'chat';
-    $event->instance    = $returnid;
-    $event->eventtype   = 'chattime';
-    $event->timestart   = $chat->chattime;
-    $event->timeduration = 0;
-
-    calendar_event::create($event);
+    if ($chat->schedule > 0) {
+        $event = new stdClass();
+        $event->name        = $chat->name;
+        $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
+        $event->courseid    = $chat->course;
+        $event->groupid     = 0;
+        $event->userid      = 0;
+        $event->modulename  = 'chat';
+        $event->instance    = $returnid;
+        $event->eventtype   = 'chattime';
+        $event->timestart   = $chat->chattime;
+        $event->timeduration = 0;
 
+        calendar_event::create($event);
+    }
     return $returnid;
 }
 
@@ -151,12 +152,35 @@ function chat_update_instance($chat) {
 
     if ($event->id = $DB->get_field('event', 'id', array('modulename' => 'chat', 'instance' => $chat->id))) {
 
-        $event->name        = $chat->name;
-        $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
-        $event->timestart   = $chat->chattime;
+        if ($chat->schedule > 0) {
+            $event->name        = $chat->name;
+            $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
+            $event->timestart   = $chat->chattime;
 
-        $calendarevent = calendar_event::load($event->id);
-        $calendarevent->update($event);
+            $calendarevent = calendar_event::load($event->id);
+            $calendarevent->update($event);
+        } else {
+            // Do not publish this event, so delete it.
+            $calendarevent = calendar_event::load($event->id);
+            $calendarevent->delete();
+        }
+    } else {
+        // No event, do we need to create one?
+        if ($chat->schedule > 0) {
+            $event = new stdClass();
+            $event->name        = $chat->name;
+            $event->description = format_module_intro('chat', $chat, $chat->coursemodule);
+            $event->courseid    = $chat->course;
+            $event->groupid     = 0;
+            $event->userid      = 0;
+            $event->modulename  = 'chat';
+            $event->instance    = $chat->id;
+            $event->eventtype   = 'chattime';
+            $event->timestart   = $chat->chattime;
+            $event->timeduration = 0;
+
+            calendar_event::create($event);
+        }
     }
 
     return true;
diff --git a/mod/chat/tests/behat/chat_calendar_events.feature b/mod/chat/tests/behat/chat_calendar_events.feature
new file mode 100644
index 00000000000..e91955bd93d
--- /dev/null
+++ b/mod/chat/tests/behat/chat_calendar_events.feature
@@ -0,0 +1,36 @@
+@mod @mod_chat
+Feature: Chat calendar entries
+  In order to notify students of upcoming chat sessons
+  As a teacher
+  I need to create a chat activity and publish the event times
+
+  Background:
+    Given the following "users" exist:
+      | username | firstname | lastname | email |
+      | teacher1 | Tina | Teacher1 | teacher1@example.com |
+      | student1 | Sam | Student1 | student1@example.com |
+    And the following "courses" exist:
+      | fullname | shortname | category |
+      | Course 1 | C1 | 0 |
+    And the following "course enrolments" exist:
+      | user | course | role |
+      | teacher1 | C1 | editingteacher |
+      | student1 | C1 | student |
+
+  Scenario: Create a chat activity and do not publish the start date to the calendar
+    Given the following "activities" exist:
+      | activity | name           | intro                 | course | idnumber | schedule |
+      | chat     | Test chat name | Test chat description | C1     | chat1    | 0 |
+    And I log in as "teacher1"
+    And I follow "Course 1"
+    When I navigate to "Calendar" node in "Site pages"
+    Then I should not see "Test chat name"
+
+  Scenario: Create a chat activity and publish the start date to the calendar
+    Given the following "activities" exist:
+      | activity | name           | intro                 | course | idnumber | schedule |
+      | chat     | Test chat name | Test chat description | C1     | chat1    | 1 |
+    And I log in as "teacher1"
+    And I follow "Course 1"
+    When I navigate to "Calendar" node in "Site pages"
+    Then I should see "Test chat name"