diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..4334054
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,4 @@
+#!/usr/bin/env sh
+
+tools/merge_cals.py
+hugo
diff --git a/content/page/amateurfunk.md b/content/page/amateurfunk.md
index 12547fd..89f6319 100644
--- a/content/page/amateurfunk.md
+++ b/content/page/amateurfunk.md
@@ -3,8 +3,8 @@ title: "Amateurfunk"
 subtitle: "Funken und Löten im CCCB"
 date: 2018-05-17T22:41:48+02:00
 dtstart: 20180709T200000
-dtend: 20180709T220000
-rrule: "FREQ=WEEKLY;BYDAY=MO;INTERVAL=1"
+dtend:   20180709T220000
+rrule:   "FREQ=WEEKLY;BYDAY=MO;INTERVAL=1"
 menu:
   main:
     parent: "veranstaltungen"
diff --git a/content/page/chaosradio.md b/content/page/chaosradio.md
index 177f824..707a7d9 100644
--- a/content/page/chaosradio.md
+++ b/content/page/chaosradio.md
@@ -2,9 +2,9 @@
 title: "Chaosradio"
 subtitle: "Der Podcast im Radio"
 date: 2018-05-17T22:47:26+02:00
-rrule: "FREQ=MONTHLY;BYSETPOS=-1;BYDAY=TH;INTERVAL=1"
 dtstart: 20180628T220000
-dtend: 20180629T000000
+dtend:   20180629T000000
+rrule:   "FREQ=MONTHLY;BYSETPOS=-1;BYDAY=TH;INTERVAL=1"
 location: "CCCB oder Fritz"
 menu:
   main:
diff --git a/content/page/clubdiscordia.md b/content/page/clubdiscordia.md
index 9f34cd1..919a22d 100644
--- a/content/page/clubdiscordia.md
+++ b/content/page/clubdiscordia.md
@@ -2,9 +2,9 @@
 title: "Club Discordia"
 subtitle: "Die offenen Abende im CCCB"
 date: 2018-05-17T22:59:56+02:00
-dtstart: 2018070300000
-dtend: 20180704T000000
-rrule: "FREQ=WEEKLY;BYDAY=TU,TH;INTERVAL=1"
+dtstart: 20180703T190000
+dtend:   20180704T000000
+rrule:   "FREQ=WEEKLY;BYDAY=TU,TH;INTERVAL=1"
 menu:
   main:
     parent: "veranstaltungen"
diff --git a/content/page/cms.md b/content/page/cms.md
index f2c5ea9..68690db 100644
--- a/content/page/cms.md
+++ b/content/page/cms.md
@@ -2,9 +2,9 @@
 title: "Chaos macht Schule"
 subtitle: "Technikkompetenzvermittlung"
 date: 2018-05-18T01:11:54+02:00
-rrule: "FREQ=MONTHLY;BYSETPOS=1;BYDAY=TH;INTERVAL=1"
 dtstart: 20180705T190000
-dtend: 20180705T230000
+dtend:   20180705T230000
+rrule:   "FREQ=MONTHLY;BYSETPOS=1;BYDAY=TH;INTERVAL=1"
 menu:
   main:
     parent: "veranstaltungen"
diff --git a/content/page/coderdojo.md b/content/page/coderdojo.md
index f613c7d..5acd302 100644
--- a/content/page/coderdojo.md
+++ b/content/page/coderdojo.md
@@ -2,7 +2,9 @@
 title: "Coder Dojo"
 subtitle: Hacken und Coden für Kinder 
 date: 2018-05-18T09:51:02+02:00
-rrule: "FREQ=MONTHLY;BYSETPOS=3;BYDAY=SA;INTERVAL=1"
+dtstart: 20180623T140000
+dtend:   20180623T170000
+rrule:   "FREQ=MONTHLY;BYSETPOS=3;BYDAY=SA;INTERVAL=1"
 menu:
   main:
     parent: "veranstaltungen"
diff --git a/content/page/plenum.md b/content/page/plenum.md
index 21daaef..4558ab0 100644
--- a/content/page/plenum.md
+++ b/content/page/plenum.md
@@ -2,9 +2,9 @@
 title: "Plenum"
 subtitle: "Instrument der internen Konsensfindung"
 date: 2018-05-18T01:11:54+02:00
-rrule: "FREQ=MONTHLY;BYSETPOS=1;BYDAY=WE;INTERVAL=1"
 dtstart: 20180704T200000
-dtend: 20180704T220000
+dtend:   20180704T220000
+rrule:   "FREQ=MONTHLY;BYSETPOS=1;BYDAY=WE;INTERVAL=1"
 menu:
   main:
     parent: "verein"
diff --git a/layouts/datengarten/section.ics b/layouts/datengarten/section.ics
index c572328..1c9da72 100644
--- a/layouts/datengarten/section.ics
+++ b/layouts/datengarten/section.ics
@@ -11,14 +11,12 @@ TZOFFSETFROM:+0100
 TZOFFSETTO:+0200
 TZNAME:CEST
 DTSTART:19700329T020000
-RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
 END:DAYLIGHT
 BEGIN:STANDARD
 TZOFFSETFROM:+0200
 TZOFFSETTO:+0100
 TZNAME:CET
 DTSTART:19701025T030000
-RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
 END:STANDARD
 END:VTIMEZONE
 BEGIN:VEVENT
diff --git a/layouts/page/single.ics b/layouts/page/single.ics
index c02ba10..086495d 100644
--- a/layouts/page/single.ics
+++ b/layouts/page/single.ics
@@ -1,5 +1,4 @@
-{{if isset .Params "rrule"}}
-BEGIN:VCALENDAR
+{{if isset .Params "rrule"}}BEGIN:VCALENDAR
 VERSION:2.0
 PRODID:-//cccb//datengarten calendar//EN
 CALSCALE:GREGORIAN
@@ -18,13 +17,12 @@ TZOFFSETFROM:+0200
 TZOFFSETTO:+0100
 TZNAME:CET
 DTSTART:19701025T030000
-RRULE:{{.Params.rrule}}
 END:STANDARD
 END:VTIMEZONE
 BEGIN:VEVENT
 ORGANIZER;CN="CCCB":mailto:mail@berlin.ccc.de
 SUMMARY:{{.Title}}
-UID: {{.Title}}@berlin.ccc.de
+UID:{{lower (replace .Title " " "")}}@berlin.ccc.de
 SEQUENCE:0
 STATUS:CONFIRMED
 DTSTAMP:20180508T200000Z
diff --git a/tools/merge_cals.py b/tools/merge_cals.py
new file mode 100755
index 0000000..463cd80
--- /dev/null
+++ b/tools/merge_cals.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+
+from glob import glob
+import icalendar
+import pytz
+
+cals=[]
+merged=icalendar.Calendar()
+merged.add('prodid', '-//CCCB Calendar Generator//berlin.ccc.de//')
+merged.add('version', '2.0') 
+
+for icsfilestr in glob("public/*/**/*.ics", recursive=True):
+	with open(icsfilestr, 'r') as icsfile:
+		print("Importing", icsfilestr)
+		cals.append(icalendar.Calendar.from_ical(icsfile.read()))
+
+for cal in cals:
+	for e in cal.subcomponents:
+		merged.add_component(e)
+
+outfile="static/all.ics"
+with open(outfile, 'wb') as f:
+	print(f"writing to {outfile}...")
+	f.write(merged.to_ical())
+