From 1f9f09fe09499a02fb1fb26fbf4c8e8bc71aeb2d Mon Sep 17 00:00:00 2001
From: Thomas Bruederli <bruederli@kolabsys.com>
Date: Wed, 23 Jan 2013 10:06:44 +0100
Subject: [PATCH] Fix ical export with (invalid) timezone +00:00

---
 plugins/calendar/lib/calendar_ical.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/plugins/calendar/lib/calendar_ical.php b/plugins/calendar/lib/calendar_ical.php
index f77224dc..cec20400 100644
--- a/plugins/calendar/lib/calendar_ical.php
+++ b/plugins/calendar/lib/calendar_ical.php
@@ -449,7 +449,8 @@ class calendar_ical
     else {
       // <ATTR>;TZID=Europe/Zurich:20120706T210000
       $tz = $dt->getTimezone();
-      $tzid = $tz && $tz->getName() != 'UTC' ? ';TZID=' . $tz->getName() : '';
+      $tzname = $tz ? $tz->getName() : null;
+      $tzid = $tzname && $tzname != 'UTC' && $tzname != '+00:00' ? ';TZID=' . $tzname : '';
       return $attr . $tzid . ':' . $dt->format('Ymd\THis' . ($tzid ? '' : '\Z'));
     }
   }