diff --git a/infomentor/icalendar_addons.py b/infomentor/icalendar_addons.py
new file mode 100644
index 0000000..d942460
--- /dev/null
+++ b/infomentor/icalendar_addons.py
@@ -0,0 +1,67 @@
+import pytz
+import icalendar
+import datetime
+
+def generate_vtimezone(timezone, for_date=None):
+    if not timezone or 'utc' in timezone.lower():  # UTC doesn't need a timezone definition
+        return None
+    if not for_date:
+        for_date = now()
+    try:
+        z = pytz.timezone(timezone)
+    except pytz.UnknownTimeZoneError:
+        z = pytz.timezone('Europe/Berlin')
+    if not hasattr(z, '_utc_transition_times'):
+        return None
+    transitions = zip(z._utc_transition_times, z._transition_info)
+    try:
+        dst1, std1, dst2, std2 = filter(lambda x: x[0].year in (for_date.year, for_date.year + 1),
+                                        transitions)
+        if dst1[1][1].seconds == 0:
+            return _vtimezone_with_dst(std1, dst1, std2, dst2, timezone)
+        else:
+            return _vtimezone_with_dst(dst1, std1, dst2, std2, timezone)
+
+    except:
+        std = transitions[-1]
+        if std[0].year > for_date.year:
+            return None
+        return _vtimezone_without_dst(std, timezone)
+
+
+def _vtimezone_without_dst(std, timezone):
+    vtimezone = icalendar.Timezone(tzid=timezone)
+    standard = icalendar.TimezoneStandard()
+    utc_offset, dst_offset, tz_name = std[1]
+    standard.add('dtstart', std[0])
+    standard.add('tzoffsetfrom', utc_offset)
+    standard.add('tzoffsetto', utc_offset)
+    standard.add('tzname', tz_name)
+    vtimezone.add_component(standard)
+    return vtimezone
+
+
+def _vtimezone_with_dst(dst1, std1, dst2, std2, timezone):
+    vtimezone = icalendar.Timezone(tzid=timezone)
+    daylight = icalendar.TimezoneDaylight()
+    utc_offset, dst_offset, tz_name = dst1[1]
+    offsetfrom = std1[1][0]
+    daylight.add('dtstart', dst1[0] + offsetfrom)
+    daylight.add('rdate', dst1[0] + offsetfrom)
+    daylight.add('rdate', dst2[0] + offsetfrom)
+    daylight.add('tzoffsetfrom', offsetfrom)
+    daylight.add('tzoffsetto', utc_offset)
+    daylight.add('tzname', tz_name)
+    vtimezone.add_component(daylight)
+
+    standard = icalendar.TimezoneStandard()
+    utc_offset, dst_offset, tz_name = std1[1]
+    offsetfrom = dst1[1][0]
+    standard.add('dtstart', std1[0] + offsetfrom)
+    standard.add('rdate', std1[0] + offsetfrom)
+    standard.add('rdate', std2[0] + offsetfrom)
+    standard.add('tzoffsetfrom', offsetfrom)
+    standard.add('tzoffsetto', utc_offset)
+    standard.add('tzname', tz_name)
+    vtimezone.add_component(standard)
+    return vtimezone
diff --git a/infomentor/informer.py b/infomentor/informer.py
index 6d21396..abeb903 100755
--- a/infomentor/informer.py
+++ b/infomentor/informer.py
@@ -1,4 +1,4 @@
-from infomentor import model, db, icloudcalendar, config
+from infomentor import model, db, icloudcalendar, config, icalendar_addons
 import logging
 import uuid
 import os
@@ -9,7 +9,7 @@ import datetime
 import math
 import pushover
 import urllib.parse
-from icalendar import Event, vDate, Calendar, vCalAddress, vText, vBoolean
+from icalendar import Event, vDate, Calendar, vCalAddress, vText, vBoolean, Timezone
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 from email.mime.base import MIMEBase
@@ -17,6 +17,7 @@ from email import encoders
 import mimetypes
 import smtplib
 
+
 cfg = config.load()
 pushover.init(cfg["pushover"]["apikey"])
 
@@ -257,6 +258,7 @@ class Informer(object):
         calobj.add("METHOD", "REQUEST")
         calobj.add("calscale", "GREGORIAN")
         calobj.add("version", "2.0")
+        calobj.add_component(icalendar_addons.generate_vtimezone('Europe/Berlin'))
         attendee = vCalAddress(f'MAILTO:{to}')
         attendee.params['cn'] = vText(to)
         attendee.params['ROLE'] = vText('REQ-PARTICIPANT')