2.3. Date handling

DTEND property was not well defined. For example, if we have event with DTSTART=20040404T100000 and DURATION=PT2H, it is not clear if the DTEND should be 120000 or 115900. We have seen iCalendars with both the conventions.

All times are written in UTC (even when the event/todo has an RRULE) — (WHY?)