calendar: improve ical export format
The following details change:
- add
PRODID:stadtgestalten
- add
X-WR-CALNAME
(recommended calendar label for clients) - add
X-WR-TIMEZONE
- add
DTEND
- add
UID
- use current timezone (instead of UTC) for
DTSTART
andDTEND
These changes were suggested by Georg.
Example calendar export:
BEGIN:VCALENDAR
VERSION:2.0
PRODID:stadtgestalten
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:foo (example.com)
X-WR-TIMEZONE:Europe/Berlin
BEGIN:VEVENT
SUMMARY:Eine Veranstaltung
DTSTART;TZID=Europe/Berlin;VALUE=DATE-TIME:20180607T210000
DTEND;TZID=Europe/Berlin;VALUE=DATE-TIME:20180607T221500
DTSTAMP;VALUE=DATE-TIME:20180528T034023Z
UID:foo.57@example.com
DESCRIPTION:Eine Veranstaltung
LOCATION:und so
URL:http://example.com/foo/eine-veranstaltung/
END:VEVENT
END:VCALENDAR