diff --git a/plugins/libcalendaring/libvcalendar.php b/plugins/libcalendaring/libvcalendar.php
index 82a7a6eb..d4765f2e 100644
--- a/plugins/libcalendaring/libvcalendar.php
+++ b/plugins/libcalendaring/libvcalendar.php
@@ -522,7 +522,7 @@ class libvcalendar implements Iterator
                     }
                 }
                 $attendee = self::map_keys($params, array_flip($this->attendee_keymap));
-                $attendee['email'] = preg_replace('/^mailto:/i', '', $value);
+                $attendee['email'] = preg_replace('!^mailto:!i', '', $value);
 
                 if ($prop->name == 'ORGANIZER') {
                     $attendee['role'] = 'ORGANIZER';
@@ -605,11 +605,9 @@ class libvcalendar implements Iterator
 
                 switch ($prop->name) {
                 case 'TRIGGER':
-                    foreach ($prop->parameters() as $pname => $pvalue) {
-                        if ($pname == 'VALUE' && $pvalue == 'DATE-TIME') {
-                            $trigger = '@' . $prop->getDateTime()->format('U');
-                            $alarm['trigger'] = $prop->getDateTime();
-                        }
+                    if ($prop['VALUE'] == 'DATE-TIME') {
+                        $trigger = '@' . $prop->getDateTime()->format('U');
+                        $alarm['trigger'] = $prop->getDateTime();
                     }
                     if (!$trigger && ($values = libcalendaring::parse_alaram_value($value))) {
                         $trigger = $values[2];
@@ -638,7 +636,7 @@ class libvcalendar implements Iterator
                     break;
 
                 case 'ATTENDEE':
-                    $alarm['attendees'][] = preg_replace('/^mailto:/i', '', $value);
+                    $alarm['attendees'][] = preg_replace('!^mailto:!i', '', $value);
                     break;
 
                 case 'ATTACH':
@@ -710,7 +708,7 @@ class libvcalendar implements Iterator
                 break;
 
             case 'ORGANIZER':
-                $this->freebusy['organizer'] = preg_replace('/^mailto:/i', '', $value);
+                $this->freebusy['organizer'] = preg_replace('!^mailto:!i', '', $value);
                 break;
 
             case 'FREEBUSY':
@@ -835,7 +833,7 @@ class libvcalendar implements Iterator
      * @param boolean Set as UTC date
      * @param boolean Set as VALUE=DATE property
      */
-    public function datetime_prop($cal, $name, $dt, $utc = false, $dateonly = null)
+    public function datetime_prop($cal, $name, $dt, $utc = false, $dateonly = null, $set_type = false)
     {
         if ($utc) {
             $dt->setTimeZone(new \DateTimeZone('UTC'));
@@ -845,12 +843,14 @@ class libvcalendar implements Iterator
             $is_utc = ($tz = $dt->getTimezone()) && in_array($tz->getName(), array('UTC','GMT','Z'));
         }
         $is_dateonly = $dateonly === null ? (bool)$dt->_dateonly : (bool)$dateonly;
-        $vdt = $cal->createProperty($name);
-        $vdt->setValue($dt);
+        $vdt = $cal->createProperty($name, $dt, null, $is_dateonly ? 'DATE' : 'DATE-TIME');
 
         if ($is_dateonly) {
             $vdt['VALUE'] = 'DATE';
         }
+        else if ($set_type) {
+            $vdt['VALUE'] = 'DATE-TIME';
+        }
 
         // register timezone for VTIMEZONE block
         if (!$is_utc && !$dateonly && $tz && ($tzname = $tz->getName())) {
@@ -1086,7 +1086,7 @@ class libvcalendar implements Iterator
                 $va = $cal->createComponent('VALARM');
                 $va->action = $alarm['action'];
                 if ($alarm['trigger'] instanceof DateTime) {
-                    $va->add($this->datetime_prop($cal, 'TRIGGER', $alarm['trigger'], true));
+                    $va->add($this->datetime_prop($cal, 'TRIGGER', $alarm['trigger'], true, null, true));
                 }
                 else {
                     $va->add('TRIGGER', $alarm['trigger']);
@@ -1121,7 +1121,7 @@ class libvcalendar implements Iterator
             if ($val[3])
                 $va->add('TRIGGER', $val[3]);
             else if ($val[0] instanceof DateTime)
-                $va->add($this->datetime_prop($cal, 'TRIGGER', $val[0]));
+                $va->add($this->datetime_prop($cal, 'TRIGGER', $val[0], true, null, true));
             $ve->add($va);
         }
 
diff --git a/plugins/libcalendaring/tests/libvcalendar.php b/plugins/libcalendaring/tests/libvcalendar.php
index 702b13cb..f97513a5 100644
--- a/plugins/libcalendaring/tests/libvcalendar.php
+++ b/plugins/libcalendaring/tests/libvcalendar.php
@@ -218,13 +218,14 @@ class libvcalendar_test extends PHPUnit_Framework_TestCase
         $this->assertEquals('DISPLAY', $event['valarms'][0]['action'],  "First alarm action");
         $this->assertEquals('This is the first event reminder', $event['valarms'][0]['description'],  "First alarm text");
 
-        $this->assertEquals(2, count($event['valarms']), "List all VALARM blocks");
+        $this->assertEquals(3, count($event['valarms']), "List all VALARM blocks");
 
         $valarm = $event['valarms'][1];
         $this->assertEquals(1, count($valarm['attendees']), "Email alarm attendees");
         $this->assertEquals('EMAIL', $valarm['action'],  "Second alarm item (action)");
         $this->assertEquals('-P1D',  $valarm['trigger'], "Second alarm item (trigger)");
         $this->assertEquals('This is the reminder message',  $valarm['summary'], "Email alarm text");
+        $this->assertInstanceOf('DateTime', $event['valarms'][2]['trigger'], "Absolute trigger date/time");
 
         // test alarms export
         $ics = $ical->export(array($event));
@@ -233,6 +234,7 @@ class libvcalendar_test extends PHPUnit_Framework_TestCase
         $this->assertContains('DESCRIPTION:This is the first event reminder',    $ics, "Alarm description");
         $this->assertContains('SUMMARY:This is the reminder message',            $ics, "Email alarm summary");
         $this->assertContains('ATTENDEE:mailto:reminder-recipient@example.org',  $ics, "Email alarm recipient");
+        $this->assertContains('TRIGGER;VALUE=DATE-TIME:20130812',  $ics, "Date-Time trigger");
     }
 
     /**
diff --git a/plugins/libcalendaring/tests/resources/alarms.ics b/plugins/libcalendaring/tests/resources/alarms.ics
index d6f9d547..9d588543 100644
--- a/plugins/libcalendaring/tests/resources/alarms.ics
+++ b/plugins/libcalendaring/tests/resources/alarms.ics
@@ -46,6 +46,11 @@ ATTENDEE:mailto:reminder-recipient@example.org
 SUMMARY:This is the reminder message
 DESCRIPTION:This is the second event reminder
 END:VALARM
+BEGIN:VALARM
+ACTION:DISPLAY
+DESCRIPTION:An absolute reminder
+TRIGGER;VALUE=DATE-TIME:20130812T160000Z
+END:VALARM
 END:VEVENT
 
 END:VCALENDAR