timezone/offset in calendar ics export from opengoo to iCal

[raboof]

Hello,

In OpenGoo 1.4.2, if you export the calendar via the ics link to iCal, all events appear shifted to a wrong time even if the timezones of the server and client match. In my case, both the server and client are set to CEST (GMT+1). If I set, for example, an event on the OpenGoo calendar at 14.00, iCal will display it at 13.00.

Is this possibly related to daylight saving time?

These excerpts compare the time definitions of an iCal-exported calendar (iCalendar v3.0 compliant) and the OpenGoo-exported calendar (iCalendar v2.0 compliant):

iCal:

Code: [Select]

[...]
BEGIN:VTIMEZONE
TZID:Europe/Zurich
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
DTSTART:19810329T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
TZNAME:CEST
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
DTSTART:19961027T030000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
TZNAME:CET
END:STANDARD
END:VTIMEZONE
[...]

OpenGoo:

Code: [Select]

[...]
BEGIN:VTIMEZONE
TZID:(GMT+1:00) Amsterdam, Berlin, Rome, Copenhagen, Brussels, Madrid, Paris
BEGIN:STANDARD
TZOFFSETFROM:0100
TZOFFSETTO:0100
END:STANDARD
END:VTIMEZONE
[...]
Notice the discrepancy between the "TZOFFSETTO" values.

[raboof]

Let me brush up this report.

Concretely, having appointments appearing at wrong times turns out to be a major hassle occasionally causing absences from meetings, and eventually inviting for temporary replacement of the integrated calendar tool with a separate tool.

I made some attempts towards fixing the problem (environment/classes/event/CalFormatUtilities.php. These are "blind", meaning that I didn't study the iCalendar specification beforehand:
1) replace

Code: [Select]

$ical_info .= "TZOFFSETTO:$tz\r\n"; with

Code: [Select]

$ical_info .= "TZOFFSETTP:0200\r\n";
2) swapping the TZOFFSETTO and TZOFFSETFROM to +0100 and +0200

3) including the "DAYLIGHT" block mimicking the iCal block

Unfortunately, none worked. Is there any chance to get in touch with the actual author of the iCalendar logic? I'd be glad to do some cooperative fixing.

[raboof]

For the archive, this problem disappeared when upgraded to 1.5.3, without need to change configurations.