diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index f24a81ae..37e86a43 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -2924,11 +2924,11 @@ class calendar extends rcube_plugin
         $append = '';
 
         // prepare a small agenda preview to be filled with actual event data on async request
-        if ($ical_objects->method == 'REQUEST') {
+        if ($ical_objects->method == 'REQUEST' && $event['start']) {
+          $date   = $this->rc->format_date($event['start'], $this->rc->config->get('date_format'), empty($event['start']->_dateonly));
           $append = html::div('calendar-agenda-preview',
-            html::tag('h3', 'preview-title', $this->gettext('agenda') . ' ' .
-              html::span('date', $this->rc->format_date($event['start'], $this->rc->config->get('date_format')))
-            ) . '%before%' . $this->mail_agenda_event_row($event, 'current') . '%after%');
+            html::tag('h3', 'preview-title', $this->gettext('agenda') . ' ' . html::span('date', $date))
+            . '%before%' . $this->mail_agenda_event_row($event, 'current') . '%after%');
         }
 
         $html .= html::div('calendar-invitebox invitebox boxinformation',
diff --git a/plugins/libcalendaring/libcalendaring.php b/plugins/libcalendaring/libcalendaring.php
index 6c33aba1..e9a4c286 100644
--- a/plugins/libcalendaring/libcalendaring.php
+++ b/plugins/libcalendaring/libcalendaring.php
@@ -315,8 +315,8 @@ class libcalendaring extends rcube_plugin
         $time_format = self::to_php_date_format($this->rc->config->get('calendar_time_format', $this->defaults['calendar_time_format']));
 
         if ($event['allday']) {
-            $fromto = $this->rc->format_date($event['start'], $date_format);
-            if (($todate = $this->rc->format_date($event['end'], $date_format)) != $fromto)
+            $fromto = $this->rc->format_date($event['start'], $date_format, false);
+            if (($todate = $this->rc->format_date($event['end'], $date_format, false)) != $fromto)
                 $fromto .= ' - ' . $todate;
         }
         else if ($duration < 86400 && $event['start']->format('d') == $event['end']->format('d')) {
diff --git a/plugins/libcalendaring/libvcalendar.php b/plugins/libcalendaring/libvcalendar.php
index b5e5e5a9..4f53494a 100644
--- a/plugins/libcalendaring/libvcalendar.php
+++ b/plugins/libcalendaring/libvcalendar.php
@@ -430,7 +430,7 @@ class libvcalendar implements Iterator
             case 'DTEND':
             case 'DUE':
                 $propmap = array('DTSTART' => 'start', 'DTEND' => 'end', 'DUE' => 'due');
-                $event[$propmap[$prop->name]] =  self::convert_datetime($prop);
+                $event[$propmap[$prop->name]] = self::convert_datetime($prop);
                 break;
 
             case 'TRANSP':
@@ -694,16 +694,14 @@ class libvcalendar implements Iterator
 
         // assign current timezone to event start/end
         if ($event['start'] instanceof DateTime) {
-            if ($this->timezone)
-                $event['start']->setTimezone($this->timezone);
+            $this->_apply_timezone($event['start']);
         }
         else {
             unset($event['start']);
         }
 
         if ($event['end'] instanceof DateTime) {
-            if ($this->timezone)
-                $event['end']->setTimezone($this->timezone);
+            $this->_apply_timezone($event['end']);
         }
         else {
             unset($event['end']);
@@ -728,6 +726,27 @@ class libvcalendar implements Iterator
         return $event;
     }
 
+    /**
+     * Apply user timezone to DateTime object
+     */
+    private function _apply_timezone(&$date)
+    {
+        if (empty($this->timezone)) {
+            return;
+        }
+
+        // For date-only we'll keep the date and time intact
+        if ($date->_dateonly) {
+            $dt = new DateTime(null, $this->timezone);
+            $dt->setDate($date->format('Y'), $date->format('n'), $date->format('j'));
+            $dt->setTime($date->format('G'), $date->format('i'), 0);
+            $date = $dt;
+        }
+        else {
+            $date->setTimezone($this->timezone);
+        }
+    }
+
     /**
      * Parse the given vfreebusy component into an array representation
      */
@@ -816,7 +835,6 @@ class libvcalendar implements Iterator
         if (empty($prop)) {
             return $as_array ? array() : null;
         }
-
         else if ($prop instanceof VObject\Property\iCalendar\DateTime) {
             if (count($prop->getDateTimes()) > 1) {
                 $dt = array();