diff --git a/apps/activity/views.py b/apps/activity/views.py
index 6a2b21ca..f172309c 100644
--- a/apps/activity/views.py
+++ b/apps/activity/views.py
@@ -338,10 +338,10 @@ END:VTIMEZONE
 DTSTAMP:{"{:%Y%m%dT%H%M%S}".format(activity.date_start)}Z
 UID:{md5((activity.name + "$" + str(activity.id) + str(activity.date_start)).encode("UTF-8")).hexdigest()}
 SUMMARY;CHARSET=UTF-8:{self.multilines(activity.name, 75, 22)}
-DTSTART;TZID=Europe/Berlin:{"{:%Y%m%dT%H%M%S}".format(activity.date_start)}
-DTEND;TZID=Europe/Berlin:{"{:%Y%m%dT%H%M%S}".format(activity.date_end)}
+DTSTART:{"{:%Y%m%dT%H%M%S}Z".format(activity.date_start)}
+DTEND:{"{:%Y%m%dT%H%M%S}Z".format(activity.date_end)}
 LOCATION:{self.multilines(activity.location, 75, 9) if activity.location else "Kfet"}
-DESCRIPTION;CHARSET=UTF-8:""" + self.multilines(activity.description.replace("\n", "\\n"), 75, 26) + """
+DESCRIPTION;CHARSET=UTF-8:""" + self.multilines(activity.description.replace("\n", "\\n"), 75, 26) + f"""
  -- {activity.organizer.name}
 END:VEVENT
 """