I generate a vcalendar file with DTSTART and DTEND with week numbers and day of week just like RFC5545 and ISO.8601.2004 1 says. Like so:
DTSTART:2015W437T200000Z
DTEND:2015W437T210000Z
or
DTSTART:2015-W43-7T200000Z
DTEND:2015-W43-7T210000Z
Which read year 2015 week 43 day 7 (Sunday) 8.00pm to 9.00pm.
But neither google-calendar nor an online validator I've come across says that it's correct. Anyone got an idea whats going on?
As the Calendar API docs state, the format does not take weeks; instead, it uses RFC3339 and should read
DTSTART:2015-10-25T20:00:00Z
DTEND:2015-10-25T21:00:00Z