The following example demonstrates the set up for a simple event notification that plays back a generic message followed by the time of the upcoming meeting. calendar.conf.
[calendar_joe] type = ical url = https://example.com/home/jdoe/Calendar user = jdoe secret = mysecret refresh = 15 timeframe = 600 autoreminder = 10 channel = SIP/joe context = calendar_event_notify extension = s waittime = 30
[calendar_event_notify] exten => s,1,Answer exten => s,n,Playback(you-have-a-meeting-at) exten => s,n,SayUnixTime(${CALENDAR_EVENT(start)}) exten => s,n,Hangup