diff --git a/blechreiz/calendarCredentials.dat b/blechreiz/calendarCredentials.dat
new file mode 100644
index 0000000..4e71385
--- /dev/null
+++ b/blechreiz/calendarCredentials.dat
@@ -0,0 +1 @@
+{"_module": "oauth2client.client", "token_expiry": "2014-04-19T18:37:13Z", "access_token": "ya29.1.AADtN_UNi3N8wJ5AiTZ3ced1ho7-ZOhe9cV0TqJ7lByEy_h5SHGm0EuZBSWVOQ3q3g", "token_uri": "https://accounts.google.com/o/oauth2/token", "invalid": false, "token_response": {"access_token": "ya29.1.AADtN_UNi3N8wJ5AiTZ3ced1ho7-ZOhe9cV0TqJ7lByEy_h5SHGm0EuZBSWVOQ3q3g", "token_type": "Bearer", "expires_in": 3600}, "client_id": "34462582242-4kpdvvbi27ajt4u22uitqurpve9o8ipj.apps.googleusercontent.com", "id_token": null, "client_secret": "y4t9XBrJdCODPTO5UvtONWWn", "revoke_uri": "https://accounts.google.com/o/oauth2/revoke", "_class": "OAuth2Credentials", "refresh_token": "1/7-6-m_lLAKX8IeD7OuGtkcIiprty_nZUSxhMunSC5b0", "user_agent": null}
\ No newline at end of file
diff --git a/blechreiz/settings.py b/blechreiz/settings.py
index 1998979..137fdd7 100644
--- a/blechreiz/settings.py
+++ b/blechreiz/settings.py
@@ -183,6 +183,8 @@ GCAL_COUPLING = {
     'clientId'          : '34462582242-4kpdvvbi27ajt4u22uitqurpve9o8ipj.apps.googleusercontent.com',
     'client_secret'     : 'y4t9XBrJdCODPTO5UvtONWWn',
     'credentials_file'  : PROJECT_PATH + '/calendarCredentials.dat',
+    'push_url'          : "https://test.bauer.technology/eventplanner_gcal/gcalApiCallback",
+    #'push_url'          : "https://test.bauer.technology/callbackTest2.php",
 }
 
 
diff --git a/blechreiz/urls.py b/blechreiz/urls.py
index bb14405..360a9bf 100644
--- a/blechreiz/urls.py
+++ b/blechreiz/urls.py
@@ -9,8 +9,9 @@ import musicians.urls
 #import imagestore.urls
 import website.urls
 import scoremanager.urls
+import eventplanner_gcal.urls
+
 
-from eventplanner_gcal.views import *
 
 import settings
 from django.conf.urls.static import static
@@ -18,13 +19,13 @@ from django.conf.urls.static import static
 admin.autodiscover()
 
 urlpatterns = patterns('',
-    url(r'^',                 include(website.urls) ),
-    url(r'^events/',          include( eventplanner.urls.urlpatterns) ),
-    url(r'^musicians/',       include( musicians.urls.urlpatterns) ),
-    url(r'^scores/',          include( scoremanager.urls.urlpatterns) ),
-    url(r'^messages/$',       simpleforum.views.message_view ),
-    url(r'^admin/',           include(admin.site.urls) ),
-    url(r'^location_field/',  include('location_field.urls')),
+    url(r'^',                   include( website.urls ) ),
+    url(r'^events/',            include( eventplanner.urls.urlpatterns) ),
+    url(r'^musicians/',         include( musicians.urls.urlpatterns) ),
+    url(r'^scores/',            include( scoremanager.urls.urlpatterns) ),
+    url(r'^messages/$',         simpleforum.views.message_view ),
+    url(r'^admin/',             include( admin.site.urls ) ),
+    url(r'^location_field/',    include( 'location_field.urls' ) ),
+    url(r'^eventplanner_gcal/', include( eventplanner_gcal.urls) ),
     #url(r'^gallery/',         include(imagestore.urls, namespace='imagestore') ),
-    url(r'^eventSync/',       runSync )
 ) + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)
diff --git a/bootstrapTheme/templates/bootstrapTheme/bootstrapTheme.html b/bootstrapTheme/templates/bootstrapTheme/bootstrapTheme.html
index 69c8926..d633e7d 100644
--- a/bootstrapTheme/templates/bootstrapTheme/bootstrapTheme.html
+++ b/bootstrapTheme/templates/bootstrapTheme/bootstrapTheme.html
@@ -6,7 +6,7 @@
 {% addtoblock "css" strip %} <link rel="stylesheet" href="{{STATIC_URL}}/css/bootstrap-overrides.css">                     {% endaddtoblock %}                                                                                         
 {% addtoblock "css" strip %} <link rel="stylesheet" href="{{STATIC_URL}}/css/theme.css" type="text/css">                   {% endaddtoblock %}                                                                                       
 {% addtoblock "css" strip %} <link rel="stylesheet" href="{{STATIC_URL}}/css/index.css" type="text/css" media="screen" />  {% endaddtoblock %}                                                                     
-{% addtoblock "css" strip %} <link href='http://fonts.googleapis.com/css?family=Lato:300,400,700,900,300italic,400italic,700italic,900italic' rel='stylesheet' type='text/css'>{% endaddtoblock %}
+{% addtoblock "css" strip %} <link href='https://fonts.googleapis.com/css?family=Lato:300,400,700,900,300italic,400italic,700italic,900italic' rel='stylesheet' type='text/css'>{% endaddtoblock %}
 
 {% addtoblock "css" %}
     <!--[if lt IE 9]>
diff --git a/eventplanner/models.py b/eventplanner/models.py
index dd1c961..91bbe01 100644
--- a/eventplanner/models.py
+++ b/eventplanner/models.py
@@ -116,8 +116,6 @@ class Event ( models.Model ):
             return nextEvent
 
 
-before_read = Signal()
-
 
 class EventParticipation( models.Model ):
     OPTIONS = ( ('?'  , _('?'  )),
@@ -147,10 +145,6 @@ class EventParticipation( models.Model ):
         else:
             return True
 
-    @staticmethod
-    def raiseBeforeReadSignal():
-        before_read.send( sender=EventParticipation )
-
     @staticmethod
     def isMember( user ):
         return user.has_perm('eventplanner.member')
diff --git a/eventplanner/urls.py b/eventplanner/urls.py
index b54df8e..685eba8 100644
--- a/eventplanner/urls.py
+++ b/eventplanner/urls.py
@@ -6,13 +6,13 @@ from eventplanner.views import events_grid, eventplanning,event_api,EventUpdate,
 
 urlpatterns = patterns('',
     url(r'^$',                   eventplanning ),
-    url(r'^grid$',               events_grid ),
+    url(r'^grid$',               events_grid   ),
     url(r'^planning$',           eventplanning ),    
     url(r'^(?P<pk>\d+)$',        permission_required('eventplanner.change_event')( EventUpdate.as_view() ) ),
-    url(r'^add$',                permission_required('eventplanner.add_event')( EventCreate.as_view() ) ),
-    url(r'^(?P<pk>\d+)/delete$', permission_required('eventplanner.delete_event')( deleteEvent ) ),
-    url(r'^api/',                event_api, name="event_api" ),
-    url(r'^api/(\w+)/$',         event_api, name="event_api_per_user" ),
-    url(r'^api/(\w+)/(\d+)$',    event_api, name="event_api_per_user_event"),
+    url(r'^add$',                permission_required('eventplanner.add_event'   )( EventCreate.as_view() ) ),
+    url(r'^(?P<pk>\d+)/delete$', permission_required('eventplanner.delete_event')( deleteEvent           ) ),
+    url(r'^api/',                event_api, name="event_api"                ),
+    url(r'^api/(\w+)/$',         event_api, name="event_api_per_user"       ),
+    url(r'^api/(\w+)/(\d+)$',    event_api, name="event_api_per_user_event" ),
 )
 
diff --git a/eventplanner/views.py b/eventplanner/views.py
index 740df69..a19bd77 100644
--- a/eventplanner/views.py
+++ b/eventplanner/views.py
@@ -61,7 +61,6 @@ def eventplanning( request ):
     """
         View for a specific user, to edit his events
     """
-    EventParticipation.raiseBeforeReadSignal()
     # non-members see the grid - but cannot edit anything
     if not EventParticipation.isMember( request.user ):
         return events_grid(request)
@@ -78,8 +77,6 @@ def eventplanning( request ):
     
 
 def events_grid( request ):
-    EventParticipation.raiseBeforeReadSignal()
-
     usernames = [ u.username for u in EventParticipation.members()  ]
     
     all_future_events = list ( Event.objects.filter( date__gte = datetime.date.today() ).order_by( 'date') )
@@ -135,7 +132,6 @@ class EventUpdate( UpdateView ):
 
 
 class EventCreate( CreateView ):
-    
     form_class = EventForm
     model = Event    
     template_name_suffix = "_update_form"
diff --git a/eventplanner_gcal/management/commands/gcal_checkSubscription.py b/eventplanner_gcal/management/commands/gcal_checkSubscription.py
new file mode 100644
index 0000000..02c7eed
--- /dev/null
+++ b/eventplanner_gcal/management/commands/gcal_checkSubscription.py
@@ -0,0 +1,9 @@
+from django.core.management.base import NoArgsCommand
+
+from eventplanner_gcal.signals import checkGCalSubscription
+
+class Command(NoArgsCommand):
+    help = 'Checks if the GCal notification channel is still active'
+    def handle_noargs(self, **options):
+         print ( "Checking Subscription")
+         checkGCalSubscription()
diff --git a/eventplanner_gcal/management/commands/gcal_delete_all.py b/eventplanner_gcal/management/commands/gcal_delete_all.py
index a01ec21..70e67b0 100644
--- a/eventplanner_gcal/management/commands/gcal_delete_all.py
+++ b/eventplanner_gcal/management/commands/gcal_delete_all.py
@@ -1,5 +1,5 @@
 from django.core.management.base import NoArgsCommand
-from eventplanner_gcal.models import deleteAllGCalEvents
+from eventplanner_gcal.signals import deleteAllGCalEvents
 
 class Command(NoArgsCommand):
     help = 'Delete all events in the google calendar created by this app'
diff --git a/eventplanner_gcal/management/commands/gcal_stopSubscriptions.py b/eventplanner_gcal/management/commands/gcal_stopSubscriptions.py
new file mode 100644
index 0000000..e3d153a
--- /dev/null
+++ b/eventplanner_gcal/management/commands/gcal_stopSubscriptions.py
@@ -0,0 +1,8 @@
+from django.core.management.base import NoArgsCommand
+
+from eventplanner_gcal.signals import stopAllGCalSubscriptions
+
+class Command(NoArgsCommand):
+    help = 'Stops all GCal subscriptions'
+    def handle_noargs(self, **options):
+         stopAllGCalSubscriptions()
diff --git a/eventplanner_gcal/management/commands/gcal_sync.py b/eventplanner_gcal/management/commands/gcal_sync.py
index 36601b1..5a215a4 100644
--- a/eventplanner_gcal/management/commands/gcal_sync.py
+++ b/eventplanner_gcal/management/commands/gcal_sync.py
@@ -1,6 +1,6 @@
 from django.core.management.base import NoArgsCommand
 
-from eventplanner_gcal.models import syncGCalEvents
+from eventplanner_gcal.signals import syncGCalEvents
 
 class Command(NoArgsCommand):
     help = 'Synchronize Google Calendar with locally stored Events'
diff --git a/eventplanner_gcal/models.py b/eventplanner_gcal/models.py
index d55df4c..3e5676e 100644
--- a/eventplanner_gcal/models.py
+++ b/eventplanner_gcal/models.py
@@ -1,3 +1,4 @@
+from apiclient.channel import new_webhook_channel, Channel
 from django.db import models
 from eventplanner.models import Event, EventParticipation
 
@@ -11,17 +12,56 @@ from django.conf import settings
 import logging
 import datetime
 from django.contrib.auth.models import User
+import time
+import uuid
 
 logger = logging.getLogger(__name__)
 
 
 
-
 class GCalMapping( models.Model ):
     gcal_id = models.CharField( max_length=64 )
     event   = models.OneToOneField( Event, primary_key=True )
 
 
+class GCalPushChannel( models.Model ):
+    """This table has either zero or one entry. Required to store if a channel already exists,
+       when it expires, and how to stop (renew) the channel
+    """
+
+    id          = models.CharField( max_length=128, primary_key=True )
+    address     = models.CharField( max_length=256 )
+    token       = models.CharField( max_length=128 )
+    resource_id = models.CharField( max_length=128 )
+    expiration  = models.IntegerField()
+
+    def toGChannel( self ):
+        return Channel( 'web_hook', self.id, self.token, self.address, self.expiration, resource_id = self.resource_id )
+
+    @staticmethod
+    def fromGChannel( gChannel ):
+        return GCalPushChannel( id         = gChannel.id,
+                                address    = gChannel.address,
+                                token      = gChannel.token,
+                                expiration = gChannel.expiration,
+                                resource_id= gChannel.resource_id )
+
+    @staticmethod
+    def createNew( callbackUrl, service, ttl = None ):
+        gChannel = Channel('web_hook', str(uuid.uuid4()), 'blechreizGcal', callbackUrl, params= { 'ttl' : int(ttl) } )
+        response = service.events().watch( calendarId='primary', body= gChannel.body() ).execute()
+        gChannel.update( response )
+
+        dbChannel = GCalPushChannel.fromGChannel( gChannel )
+        dbChannel.save()
+
+    @staticmethod
+    def stop( service, gChannel ):
+        channelService = service.channels()
+        channelService.stop( body = gChannel.body() ).execute()
+        GCalPushChannel.fromGChannel( gChannel ).delete()
+
+
 
 
 
@@ -40,8 +80,8 @@ def init( gcal_settings ):
                    http=http, developerKey=gcal_settings['developerKey'] )
 
 
-service = init( settings.GCAL_COUPLING )
 
+service = init( settings.GCAL_COUPLING )
 
 
 def createAttendeesObj( event ):
@@ -217,7 +257,6 @@ def syncGCalEvents():
 
 def syncParticipationFromGoogleToLocal():
     allEvents = getAllGCalEvents(fromNow=True)
-
     for e in allEvents:
         localId    = e['extendedProperties']['private']['blechreizID']
         localEvent = Event.objects.get( pk=localId )
@@ -236,4 +275,47 @@ def syncParticipationFromGoogleToLocal():
             else:
                 logger.error("Unknown response status when mapping gcal event: " + a['responseStatus'] )
 
-            part.save()
\ No newline at end of file
+            part.save()
+
+
+def checkGCalSubscription():
+    global service
+    callbackUrl = settings.GCAL_COUPLING['push_url']
+
+    #timeToLive        = 14*24*3600 # how long the channel should be active
+    #renewBeforeExpiry =  2*24*3600 # duration before expiry when channel is renewed
+    timeToLive = 60*5
+    renewBeforeExpiry = 60*3
+
+    # Test if a channel already exists for this callbackURL
+    try:
+        dbChannel = GCalPushChannel.objects.get( address=callbackUrl )
+        gChannel = dbChannel.toGChannel()
+
+        # if expiration time between 0 and two days: stop and create new channel
+        curTime = int( time.time() * 1000)
+        if gChannel.expiration > curTime:
+            # not yet expired
+            if curTime + renewBeforeExpiry*1000 > gChannel.expiration:
+                #will expire in less than "renewBeforeExpiry"
+                print ( "Renewing Google Calendar Subscription: " + callbackUrl )
+                GCalPushChannel.stop( service, gChannel )
+                GCalPushChannel.createNew( callbackUrl, service, timeToLive )
+            else:
+                print ("Channel active until %d " % ( gChannel.expiration, ) )
+        else:
+            print( "Google calendar subscription had expired - getting new subscription" )
+            syncParticipationFromGoogleToLocal()
+            GCalPushChannel.createNew( callbackUrl, service, timeToLive )
+
+    except GCalPushChannel.DoesNotExist:
+        # create new channel and save it in database
+        print ( "No CGalCallback Channel exists yet for: " + callbackUrl )
+        syncParticipationFromGoogleToLocal()
+        GCalPushChannel.createNew( callbackUrl, service,  timeToLive )
+
+
+def stopAllGCalSubscriptions():
+    for dbChannel in GCalPushChannel.objects.all():
+        print("Stopping %s expiry at %d " % ( dbChannel.id, dbChannel.expiration ) )
+        GCalPushChannel.stop( service, dbChannel.toGChannel() )
\ No newline at end of file
diff --git a/eventplanner_gcal/signals.py b/eventplanner_gcal/signals.py
index f5b6239..1ab599e 100644
--- a/eventplanner_gcal/signals.py
+++ b/eventplanner_gcal/signals.py
@@ -1,10 +1,10 @@
 from django.db.models.signals import post_save,pre_delete
 from django.dispatch import receiver
-from eventplanner.models import Event, EventParticipation, before_read
+from eventplanner.models import Event, EventParticipation
+from django.contrib.auth.models import User
 
-from eventplanner_gcal.models import createGCalEvent, updateGCalEvent
-from eventplanner_gcal.models import deleteGCalEvent, syncParticipationFromGoogleToLocal
 
+import eventplanner_gcal.models
 
 class SignalLock:
     def __init__(self):
@@ -25,6 +25,12 @@ class SignalLock:
 
 signalLock = SignalLock()
 
+@receiver( post_save, sender=User )
+def user_changed( **kwargs ):
+    if not signalLock.isLocked():
+        with signalLock:
+            eventplanner_gcal.models.syncGCalEvents()
+
 
 @receiver( post_save,sender= Event)
 def event_post_save_handler( **kwargs):
@@ -34,10 +40,10 @@ def event_post_save_handler( **kwargs):
             created = kwargs['created']
             if created:
                 print("Creating Gcal event")
-                createGCalEvent( event ).execute()
+                eventplanner_gcal.models.createGCalEvent( event ).execute()
             else:
                 print( "Updating Gcal event")
-                updateGCalEvent( event ).execute()
+                eventplanner_gcal.models.updateGCalEvent( event ).execute()
 
 
 
@@ -47,7 +53,7 @@ def event_pre_delete_handler( **kwargs):
         with signalLock:
             event = kwargs['instance']
             print ("Deleting GCAL event")
-            deleteGCalEvent( event ).execute()
+            eventplanner_gcal.models.deleteGCalEvent( event ).execute()
 
 
 @receiver( post_save, sender=EventParticipation )
@@ -56,12 +62,32 @@ def participation_post_save_handler( **kwargs):
         with signalLock:
             participation = kwargs['instance']
             print("Participation post save -> update gcal")
-            updateGCalEvent( participation.event ).execute()
+            eventplanner_gcal.models.updateGCalEvent( participation.event ).execute()
 
 
-@receiver( before_read, sender=EventParticipation )
-def participation_before_read_handler( **kwargs):
+
+
+# -------------- For management commands ------------------------
+
+
+def stopAllGCalSubscriptions():
     if not signalLock.isLocked():
         with signalLock:
-            print("SyncParticipation from google")
-            syncParticipationFromGoogleToLocal()
\ No newline at end of file
+            eventplanner_gcal.models.stopAllGCalSubscriptions()
+
+def checkGCalSubscription():
+    if not signalLock.isLocked():
+        with signalLock:
+            eventplanner_gcal.models.checkGCalSubscription()
+
+
+def deleteAllGCalEvents():
+    if not signalLock.isLocked():
+        with signalLock:
+            eventplanner_gcal.models.deleteAllGCalEvents()
+
+def syncGCalEvents():
+    if not signalLock.isLocked():
+        with signalLock:
+            eventplanner_gcal.models.syncGCalEvents()
+
diff --git a/eventplanner_gcal/urls.py b/eventplanner_gcal/urls.py
new file mode 100644
index 0000000..3902b87
--- /dev/null
+++ b/eventplanner_gcal/urls.py
@@ -0,0 +1,9 @@
+from django.conf.urls import patterns, url
+
+from views import runSync, gcalApiCallback
+
+urlpatterns = patterns('',
+    url(r'^runSync$',            runSync         ),
+    url(r'^gcalApiCallback$',    gcalApiCallback ),
+)
+
diff --git a/eventplanner_gcal/views.py b/eventplanner_gcal/views.py
index d61ba5f..4a63dce 100644
--- a/eventplanner_gcal/views.py
+++ b/eventplanner_gcal/views.py
@@ -1,8 +1,20 @@
 from django.shortcuts import  redirect
+from eventplanner_gcal.models import syncGCalEvents, syncParticipationFromGoogleToLocal
 
-from eventplanner_gcal.models import syncGCalEvents
 
 def runSync( request ):
     syncGCalEvents()
     return redirect("/")
 
+
+def gcalApiCallback( request ):
+    syncParticipationFromGoogleToLocal()
+    print ( "gcalApiCallback called" )
+    return redirect("/")
+
+
+
+
+
+
+
diff --git a/website/templates/website/base.html b/website/templates/website/base.html
index 5809ecb..a4b90b1 100644
--- a/website/templates/website/base.html
+++ b/website/templates/website/base.html
@@ -37,7 +37,7 @@
                 	<li><a href="/events">  Termine</a></li>	         
   	                <li><a href="/messages">Forum</a></li>
   	                <li><a href="/musicians">Adressbuch</a></li>
-                    <li><a href="/scores">   Noten</a></li>
+                    <!-- <li><a href="/scores">   Noten</a></li> -->
                 	{% endblock %}
                 	
             	    {% if user.is_authenticated %}