Google Caldav API : issue with event rrule until?

Question

I just met a problem with the API of Google Caldav on a recurring event with an end date

For example, if I have reccuring event every day between 15h and 17h until 31/08/2016, the ical event indicated :

RRULE=FREQ=WEEKLY;UNTIL=20160831T130000Z;BYDAY=TU,WE,TH,FR,SA

it should not be more (end of event) : UNTIL=20160831T150000Z ?

Thanks for you help

Damien

Answer 1

Presumably your recurring event goes from 15:00-17:00 in CET or a similar timezone. CET in summertime is UTC +2 hours, so this is correct:

UNTIL=20160831T130000Z

13:00 UTC is 15:00 CET. The Z suffix marks the DATETIME values as UTC (read RFC 5545, "FORM #2: DATE WITH UTC TIME")

Answer 2

The recurrence stuff always refers to the start of the instances. So UNTIL specifies the last permissible start date(-time) of an instance. The actual duration of the instances doesn't matter at all.

I think RFC 5545 doesn't state this explicitly, but I think it becomes clear if you read through all the sections about recurrence.