diff --git a/includes/activitypub/transformer/class-eventin.php b/includes/activitypub/transformer/class-eventin.php
index 7b4dab7..b47d93e 100644
--- a/includes/activitypub/transformer/class-eventin.php
+++ b/includes/activitypub/transformer/class-eventin.php
@@ -53,16 +53,14 @@ final class Eventin extends Event {
 	 * Get the end time from the event object.
 	 */
 	public function get_start_time(): string {
-		$datetime = new DateTime( $this->event_model->get_start_datetime(), new DateTimeZone( $this->event_model->get_timezone() ) );
-		return \gmdate( 'Y-m-d\TH:i:s\Z', $datetime->getTimestamp() );
+		return \gmdate( 'Y-m-d\TH:i:s\Z', strtotime( $this->event_model->get_start_datetime() ) );
 	}
 
 	/**
 	 * Get the end time from the event object.
 	 */
 	public function get_end_time(): string {
-		$datetime = new DateTime( $this->event_model->get_end_datetime(), new DateTimeZone( $this->event_model->get_timezone() ) );
-		return \gmdate( 'Y-m-d\TH:i:s\Z', $datetime->getTimestamp() );
+		return \gmdate( 'Y-m-d\TH:i:s\Z', strtotime( $this->event_model->get_end_datetime() ) );
 	}
 
 	/**
diff --git a/tests/test-class-plugin-eventin.php b/tests/test-class-plugin-eventin.php
index a4acc05..d844922 100644
--- a/tests/test-class-plugin-eventin.php
+++ b/tests/test-class-plugin-eventin.php
@@ -9,6 +9,22 @@
  * Test cases for WP Event Solution.
  */
 class Test_Eventin extends WP_UnitTestCase {
+	/**
+	 * Basic Mock-up event.
+	 */
+	private function get_mockup_event(): array {
+		return array(
+			'post_status'    => 'publish',
+			'post_title'     => 'Eventin Test Event Title',
+			'post_content'   => 'Eventin Test Event Description',
+			'etn_start_date' => \gmdate( 'Y-m-d', strtotime( '+10 days 15:00:00' ) ),
+			'etn_end_date'   => \gmdate( 'Y-m-d', strtotime( '+10 days 16:00:00' ) ),
+			'etn_start_time' => \gmdate( 'H:i', strtotime( '+10 days 15:00:00' ) ),
+			'etn_end_time'   => \gmdate( 'H:i', strtotime( '+10 days 16:00:00' ) ),
+			'event_timezone' => 'Europe/Vienna',
+		);
+	}
+
 	/**
 	 * Override the setup function, so that tests don't run if the Events Calendar is not active.
 	 */
@@ -41,22 +57,11 @@ class Test_Eventin extends WP_UnitTestCase {
 		$this->assertContains( 'etn', get_option( 'activitypub_support_post_types' ) );
 
 		// Create a Eventin Event without content.
-		$event_model = new \Etn\Core\Event\Event_Model();
-		$event_model->create(
-			array(
-				'post_status'    => 'publish',
-				'post_title'     => 'Eventin Test Event Title',
-				'post_content'   => 'Eventin Test Event Description',
-				'etn_start_date' => \gmdate( 'Y-m-d', strtotime( '+10 days 15:00:00' ) ),
-				'etn_end_date'   => \gmdate( 'Y-m-d', strtotime( '+10 days 16:00:00' ) ),
-				'etn_start_time' => \gmdate( 'H:i', strtotime( '+10 days 15:00:00' ) ),
-				'etn_end_time'   => \gmdate( 'H:i', strtotime( '+10 days 15:00:00' ) ),
-				'event_timezone' => 'Europe/Vienna',
-			)
-		);
+		$event = new \Etn\Core\Event\Event_Model();
+		$event->create( $this->get_mockup_event() );
 
 		// Call the transformer Factory.
-		$transformer = \Activitypub\Transformer\Factory::get_transformer( get_post( $event_model->id ) );
+		$transformer = \Activitypub\Transformer\Factory::get_transformer( get_post( $event->id ) );
 
 		// Check that we got the right transformer.
 		$this->assertInstanceOf( \ActivityPub_Event_Bridge\Activitypub\Transformer\Eventin::class, $transformer );
@@ -66,29 +71,9 @@ class Test_Eventin extends WP_UnitTestCase {
 	 * Test that the right transformer gets applied.
 	 */
 	public function test_eventin_test_minimal_event() {
-		// We only test for one event plugin being active at the same time,
-		// even though we support multiple onces in theory.
-		// But testing all combinations is beyond scope.
-		$active_event_plugins = \ActivityPub_Event_Bridge\Setup::get_instance()->get_active_event_plugins();
-		$this->assertEquals( 1, count( $active_event_plugins ) );
-
-		// Enable ActivityPub support for the event plugin.
-		$this->assertContains( 'etn', get_option( 'activitypub_support_post_types' ) );
-
 		// Create a Eventin Event without content.
 		$event = new \Etn\Core\Event\Event_Model();
-		$event->create(
-			array(
-				'post_status'    => 'publish',
-				'post_title'     => 'Eventin Test Event Title',
-				'post_content'   => 'Eventin Test Event Description',
-				'etn_start_date' => \gmdate( 'Y-m-d', strtotime( '+10 days 15:00:00' ) ),
-				'etn_end_date'   => \gmdate( 'Y-m-d', strtotime( '+10 days 16:00:00' ) ),
-				'etn_start_time' => '03:00 PM',
-				'etn_end_time'   => '04:00 PM',
-				'event_timezone' => 'Europe/Vienna',
-			)
-		);
+		$event->create( $this->get_mockup_event() );
 
 		// Call the transformer Factory.
 		$event_array = \Activitypub\Transformer\Factory::get_transformer( get_post( $event->id ) )->to_object()->to_array();
@@ -96,12 +81,95 @@ class Test_Eventin extends WP_UnitTestCase {
 		$this->assertEquals( 'Event', $event_array['type'] );
 		$this->assertEquals( 'Eventin Test Event Title', $event_array['name'] );
 		$this->assertEquals( 'Eventin Test Event Description', wp_strip_all_tags( $event_array['content'] ) );
-		$this->assertEquals( gmdate( 'Y-m-d', strtotime( '+10 days 15:00:00' ) ) . 'T15:00:00Z', $event_array['startTime'] );
+		$this->assertEquals( gmdate( 'Y-m-d\TH:i:s\Z', strtotime( '+10 days 15:00:00' ) ), $event_array['startTime'] );
+		$this->assertEquals( gmdate( 'Y-m-d\TH:i:s\Z', strtotime( '+10 days 16:00:00' ) ), $event_array['endTime'] );
+		$this->assertEquals( 'Europe/Vienna', $event_array['timezone'] );
 		$this->assertEquals( comments_open( $event->id ), $event_array['commentsEnabled'] );
 		$this->assertEquals( comments_open( $event->id ) ? 'allow_all' : 'closed', $event_array['repliesModerationOption'] );
 		$this->assertEquals( 'external', $event_array['joinMode'] );
 		$this->assertArrayNotHasKey( 'location', $event_array );
-		$this->assertArrayNotHasKey( 'endTime', $event_array );
 		$this->assertEquals( 'MEETING', $event_array['category'] );
+		$this->assertEquals( false, $event_array['isOnline'] );
+	}
+
+	/**
+	 * Test that the right transformer gets applied.
+	 */
+	public function test_eventin_test_online_event_with_custom_link() {
+		// Create a Eventin Event without content.
+		$event = new \Etn\Core\Event\Event_Model();
+		$args  = array_merge(
+			$this->get_mockup_event(),
+			array(
+				'event_type' => 'online',
+				'location'   => array(
+					'integration' => 'custom_url',
+					'custom_url'  => 'https://jit.si/eventmeeting',
+				),
+			)
+		);
+		$event->create( $args );
+
+		// Call the transformer Factory.
+		$event_array = \Activitypub\Transformer\Factory::get_transformer( get_post( $event->id ) )->to_object()->to_array();
+
+		$this->assertEquals( 'Event', $event_array['type'] );
+		$this->assertEquals( 'Eventin Test Event Title', $event_array['name'] );
+		$this->assertEquals( 'Eventin Test Event Description', wp_strip_all_tags( $event_array['content'] ) );
+		$this->assertEquals( gmdate( 'Y-m-d\TH:i:s\Z', strtotime( '+10 days 15:00:00' ) ), $event_array['startTime'] );
+		$this->assertEquals( gmdate( 'Y-m-d\TH:i:s\Z', strtotime( '+10 days 16:00:00' ) ), $event_array['endTime'] );
+		$this->assertEquals( 'Europe/Vienna', $event_array['timezone'] );
+		$this->assertEquals( comments_open( $event->id ), $event_array['commentsEnabled'] );
+		$this->assertEquals( comments_open( $event->id ) ? 'allow_all' : 'closed', $event_array['repliesModerationOption'] );
+		$this->assertEquals( 'external', $event_array['joinMode'] );
+		$this->assertArrayNotHasKey( 'location', $event_array );
+		$this->assertEquals( 'MEETING', $event_array['category'] );
+		$this->assertEquals( true, $event_array['isOnline'] );
+		$this->assertContains(
+			array(
+				'type'      => 'Link',
+				'mediaType' => 'text/html',
+				'name'      => 'https://jit.si/eventmeeting',
+				'href'      => 'https://jit.si/eventmeeting',
+			),
+			$event_array['attachment']
+		);
+	}
+
+
+	/**
+	 * Test that the right transformer gets applied.
+	 */
+	public function test_eventin_test_online_event_with_physical_location() {
+		// Create a Eventin Event without content.
+		$event = new \Etn\Core\Event\Event_Model();
+		$args  = array_merge(
+			$this->get_mockup_event(),
+			array(
+				'event_type' => 'offline',
+				'location'   => array(
+					'address' => 'The NlNet center',
+				),
+			)
+		);
+		$event->create( $args );
+
+		// Call the transformer Factory.
+		$event_array = \Activitypub\Transformer\Factory::get_transformer( get_post( $event->id ) )->to_object()->to_array();
+
+		$this->assertEquals( 'Event', $event_array['type'] );
+		$this->assertEquals( 'Eventin Test Event Title', $event_array['name'] );
+		$this->assertEquals( 'Eventin Test Event Description', wp_strip_all_tags( $event_array['content'] ) );
+		$this->assertEquals( gmdate( 'Y-m-d\TH:i:s\Z', strtotime( '+10 days 15:00:00' ) ), $event_array['startTime'] );
+		$this->assertEquals( gmdate( 'Y-m-d\TH:i:s\Z', strtotime( '+10 days 16:00:00' ) ), $event_array['endTime'] );
+		$this->assertEquals( 'Europe/Vienna', $event_array['timezone'] );
+		$this->assertEquals( comments_open( $event->id ), $event_array['commentsEnabled'] );
+		$this->assertEquals( comments_open( $event->id ) ? 'allow_all' : 'closed', $event_array['repliesModerationOption'] );
+		$this->assertEquals( 'external', $event_array['joinMode'] );
+		$this->assertArrayHasKey( 'location', $event_array );
+		$this->assertEquals( 'MEETING', $event_array['category'] );
+		$this->assertEquals( false, $event_array['isOnline'] );
+		$this->assertEquals( 'The NlNet center', $event_array['location']['address'] );
+		$this->assertEquals( 'The NlNet center', $event_array['location']['name'] );
 	}
 }