When uploading an event at 16 Feb 2017 10:00 Eastern standard time, DAVdroid puts this event + ical4j timezone definition to the server:
BEGIN:VCALENDAR
VERSION:2.0
PRODID:+//IDN bitfire.at//DAVdroid/1.4.0.2 ical4android ical4j/2.x
BEGIN:VEVENT
DTSTAMP:20170219T175556Z
UID:20170219T175554Z-b17c600e48506c59
DTSTART;TZID=America/New_York:20170216T100000
DTEND;TZID=America/New_York:20170216T110000
SUMMARY:Test
STATUS:TENTATIVE
END:VEVENT
BEGIN:VTIMEZONE
TZID:America/New_York
TZURL:http://tzurl.org/zoneinfo/America/New_York
X-LIC-LOCATION:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20070311T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20071104T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
END:STANDARD
END:VTIMEZONE
END:VCALENDAR
(empty lines for visual separation)
Then, Horde converts this to this and sends it back (as an updated event):
BEGIN:VCALENDAR
VERSION:2.0
X-WR-CALNAME:Cal Of Thrones
PRODID:-//The Horde Project//Horde iCalendar Library//EN
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20170216T090000
DTEND;TZID=America/New_York:20170216T100000
DTSTAMP:20170219T175649Z
UID:20170219T175554Z-b17c600e48506c59
CREATED:20170219T175634Z
LAST-MODIFIED:20170219T175634Z
SUMMARY:Test
CLASS:PUBLIC
STATUS:TENTATIVE
TRANSP:OPAQUE
END:VEVENT
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0400 !!!!
TZOFFSETTO:-0400
DTSTART:20070311T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYMONTHDAY=8,9,10,11,12,13,14;BYDAY=1SU
TZNAME:EDT
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
DTSTART:20071104T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
TZNAME:EST
END:STANDARD
END:VTIMEZONE
END:VCALENDAR
As you can see, the daylight definition switches from a -4:00 offset to -4:00, while standard time switches from -4 to -5.
So this is a timezone problem of Horde (specifically in the DAYLIGHT
definition) and not a DAVdroid problem. Please contact Horde regarding this.
I don’t know why SOGo has this problem, too. Maybe there’s a problem with the tzdata, but in this case, I can’t do anything, too.
If there are any indications that this could be a DAVdroid problem, feel free to post here again.