diff --git a/mod/lesson/lib.php b/mod/lesson/lib.php
index c87e56466e6..fd2caadf74e 100644
--- a/mod/lesson/lib.php
+++ b/mod/lesson/lib.php
@@ -154,6 +154,7 @@ function lesson_update_events($lesson, $override = null) {
         }
 
         $event = new stdClass();
+        $event->type = !$deadline ? CALENDAR_EVENT_TYPE_ACTION : CALENDAR_EVENT_TYPE_STANDARD;
         $event->description = format_module_intro('lesson', $lesson, $cmid);
         // Events module won't show user events when the courseid is nonzero.
         $event->courseid    = ($userid) ? 0 : $lesson->course;
@@ -163,8 +164,9 @@ function lesson_update_events($lesson, $override = null) {
         $event->instance    = $lesson->id;
         $event->timestart   = $available;
         $event->timeduration = max($deadline - $available, 0);
+        $event->timesort    = $available;
         $event->visible     = instance_is_visible('lesson', $lesson);
-        $event->eventtype   = 'open';
+        $event->eventtype   = LESSON_EVENT_TYPE_OPEN;
 
         // Determine the event name and priority.
         if ($groupid) {
@@ -215,9 +217,11 @@ function lesson_update_events($lesson, $override = null) {
                 } else {
                     unset($event->id);
                 }
+                $event->type      = CALENDAR_EVENT_TYPE_ACTION;
                 $event->name      = $eventname.' ('.get_string('lessoncloses', 'lesson').')';
                 $event->timestart = $deadline;
-                $event->eventtype = 'close';
+                $event->timesort  = $deadline;
+                $event->eventtype = LESSON_EVENT_TYPE_CLOSE;
                 if ($groupid && $grouppriorities !== null) {
                     $closepriorities = $grouppriorities['close'];
                     if (isset($closepriorities[$deadline])) {
@@ -722,7 +726,7 @@ function lesson_cron () {
  * @global object
  * @param int $lessonid id of lesson
  * @param int $userid optional user id, 0 means all users
- * @return array array of grades
+ * @return array array of grades, false if none
  */
 function lesson_get_user_grades($lesson, $userid=0) {
     global $CFG, $DB;
@@ -1562,3 +1566,26 @@ function lesson_check_updates_since(cm_info $cm, $from, $filter = array()) {
 
     return $updates;
 }
+
+/**
+ * Handles creating actions for events.
+ *
+ * @param \core_calendar\event $event
+ * @param \core_calendar\action_factory $factory
+ * @return \core_calendar\local\event\value_objects\action|\core_calendar\local\interfaces\action_interface|null
+ */
+function mod_lesson_core_calendar_provide_event_action(\core_calendar\event $event,
+                                                       \core_calendar\action_factory $factory) {
+    global $DB, $CFG;
+    require_once($CFG->dirroot . '/mod/lesson/locallib.php');
+
+    $cm = get_fast_modinfo($event->courseid)->instances['lesson'][$event->instance];
+    $lesson = new lesson($DB->get_record('lesson', array('id' => $cm->instance), '*', MUST_EXIST));
+
+    return $factory->create_instance(
+        get_string('startlesson', 'lesson'),
+        new \moodle_url('/mod/lesson/view.php', ['id' => $cm->id]),
+        1,
+        $lesson->is_accessible()
+    );
+}
diff --git a/mod/lesson/locallib.php b/mod/lesson/locallib.php
index 20dc123da3d..4cabf511e0f 100644
--- a/mod/lesson/locallib.php
+++ b/mod/lesson/locallib.php
@@ -61,6 +61,10 @@ define("LESSON_MAX_EVENT_LENGTH", "432000");
 /** Answer format is HTML */
 define("LESSON_ANSWER_HTML", "HTML");
 
+// Event types.
+define('LESSON_EVENT_TYPE_OPEN', 'open');
+define('LESSON_EVENT_TYPE_CLOSE', 'close');
+
 //////////////////////////////////////////////////////////////////////////////////////
 /// Any other lesson functions go here.  Each of them must have a name that
 /// starts with lesson_
diff --git a/mod/lesson/tests/lib_test.php b/mod/lesson/tests/lib_test.php
index 4969c5e11ec..5f687449af3 100644
--- a/mod/lesson/tests/lib_test.php
+++ b/mod/lesson/tests/lib_test.php
@@ -164,4 +164,129 @@ class mod_lesson_lib_testcase extends advanced_testcase {
         $this->assertTrue($updates->timers->updated);
         $this->assertCount(1, $updates->timers->itemids);
     }
+
+    public function test_lesson_core_calendar_provide_event_action_open() {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+        // Create a course.
+        $course = $this->getDataGenerator()->create_course();
+        // Create a lesson activity.
+        $lesson = $this->getDataGenerator()->create_module('lesson', array('course' => $course->id,
+            'available' => time() - DAYSECS, 'deadline' => time() + DAYSECS));
+        // Create a calendar event.
+        $event = $this->create_action_event($course->id, $lesson->id, LESSON_EVENT_TYPE_OPEN);
+        // Create an action factory.
+        $factory = new \core_calendar\action_factory();
+        // Decorate action event.
+        $actionevent = mod_lesson_core_calendar_provide_event_action($event, $factory);
+        // Confirm the event was decorated.
+        $this->assertInstanceOf('\core_calendar\local\event\value_objects\action', $actionevent);
+        $this->assertEquals(get_string('startlesson', 'lesson'), $actionevent->get_name());
+        $this->assertInstanceOf('moodle_url', $actionevent->get_url());
+        $this->assertEquals(1, $actionevent->get_item_count());
+        $this->assertTrue($actionevent->is_actionable());
+    }
+
+    public function test_lesson_core_calendar_provide_event_action_closed() {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        // Create a course.
+        $course = $this->getDataGenerator()->create_course();
+
+        // Create a lesson activity.
+        $lesson = $this->getDataGenerator()->create_module('lesson', array('course' => $course->id,
+            'deadline' => time() - DAYSECS));
+
+        // Create a calendar event.
+        $event = $this->create_action_event($course->id, $lesson->id, LESSON_EVENT_TYPE_OPEN);
+
+        // Create an action factory.
+        $factory = new \core_calendar\action_factory();
+
+        // Decorate action event.
+        $actionevent = mod_lesson_core_calendar_provide_event_action($event, $factory);
+
+        // Confirm the event was decorated.
+        $this->assertInstanceOf('\core_calendar\local\event\value_objects\action', $actionevent);
+        $this->assertEquals(get_string('startlesson', 'lesson'), $actionevent->get_name());
+        $this->assertInstanceOf('moodle_url', $actionevent->get_url());
+        $this->assertEquals(1, $actionevent->get_item_count());
+        $this->assertFalse($actionevent->is_actionable());
+    }
+
+    public function test_lesson_core_calendar_provide_event_action_open_in_future() {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        // Create a course.
+        $course = $this->getDataGenerator()->create_course();
+
+        // Create a lesson activity.
+        $lesson = $this->getDataGenerator()->create_module('lesson', array('course' => $course->id,
+            'available' => time() + DAYSECS));
+
+        // Create a calendar event.
+        $event = $this->create_action_event($course->id, $lesson->id, LESSON_EVENT_TYPE_OPEN);
+
+        // Create an action factory.
+        $factory = new \core_calendar\action_factory();
+
+        // Decorate action event.
+        $actionevent = mod_lesson_core_calendar_provide_event_action($event, $factory);
+
+        // Confirm the event was decorated.
+        $this->assertInstanceOf('\core_calendar\local\event\value_objects\action', $actionevent);
+        $this->assertEquals(get_string('startlesson', 'lesson'), $actionevent->get_name());
+        $this->assertInstanceOf('moodle_url', $actionevent->get_url());
+        $this->assertEquals(1, $actionevent->get_item_count());
+        $this->assertFalse($actionevent->is_actionable());
+    }
+
+    public function test_lesson_core_calendar_provide_event_action_no_time_specified() {
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        // Create a course.
+        $course = $this->getDataGenerator()->create_course();
+
+        // Create a lesson activity.
+        $lesson = $this->getDataGenerator()->create_module('lesson', array('course' => $course->id));
+
+        // Create a calendar event.
+        $event = $this->create_action_event($course->id, $lesson->id, LESSON_EVENT_TYPE_OPEN);
+
+        // Create an action factory.
+        $factory = new \core_calendar\action_factory();
+
+        // Decorate action event.
+        $actionevent = mod_lesson_core_calendar_provide_event_action($event, $factory);
+
+        // Confirm the event was decorated.
+        $this->assertInstanceOf('\core_calendar\local\event\value_objects\action', $actionevent);
+        $this->assertEquals(get_string('startlesson', 'lesson'), $actionevent->get_name());
+        $this->assertInstanceOf('moodle_url', $actionevent->get_url());
+        $this->assertEquals(1, $actionevent->get_item_count());
+        $this->assertTrue($actionevent->is_actionable());
+    }
+
+    /**
+     * Creates an action event.
+     *
+     * @param int $courseid
+     * @param int $instanceid The lesson id.
+     * @param string $eventtype The event type. eg. LESSON_EVENT_TYPE_OPEN.
+     * @return bool|\core_calendar\event
+     */
+    private function create_action_event($courseid, $instanceid, $eventtype) {
+        $event = new stdClass();
+        $event->name = 'Calendar event';
+        $event->modulename  = 'lesson';
+        $event->courseid = $courseid;
+        $event->instance = $instanceid;
+        $event->type = CALENDAR_EVENT_TYPE_ACTION;
+        $event->eventtype = $eventtype;
+        $event->timestart = time();
+        return \core_calendar\event::create($event);
+    }
 }