[Tickets #12843] Re: Wrong timezone calculation with CalDAV

[noreply at bugs.horde.org]

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Ticket URL: http://bugs.horde.org/ticket/12843
------------------------------------------------------------------------------
  Ticket             | 12843
  Updated By         | nicolas at deffayet.com
  Summary            | Wrong timezone calculation with CalDAV
  Queue              | Kronolith
  Version            | 4.1.4
  Type               | Bug
  State              | Feedback
  Priority           | 1. Low
  Milestone          |
  Patch              |
  Owners             |
------------------------------------------------------------------------------


nicolas at deffayet.com (2013-11-22 19:11) wrote:

I'm sorry, there is really a problem as you can see bellow.
Can you please tell me how the timezone parsing is done in Horde when  
importing ICS data ?

Did Horde use TZID and/or X-LIC-LOCATION line or use only DTSTART/DTEND ?

As you can see bellow, when timezone in TZID and X-LIC-LOCATION lines  
are different than timezone in DTSTART and DTEND lines it works.

--->
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//dmfs.org//mimedir.icalendar//EN
BEGIN:VTIMEZONE
TZID:Europe/Berlin
X-LIC-LOCATION:Europe/Berlin
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Berlin:20131119T180000
DESCRIPTION:Some Description
SUMMARY:CalDAV-Sync Test Event
LOCATION:Some Location
TRANSP:OPAQUE
STATUS:CONFIRMED
DTEND;TZID=Europe/Berlin:20131119T190000
LAST-MODIFIED:20131118T133721Z
DTSTAMP:20131118T133721Z
CREATED:20131118T133721Z
UID:d9efd40a-39b5-4d62-9129-83ff649fa1a8
BEGIN:VALARM
TRIGGER;VALUE=DURATION:-PT10M
ACTION:DISPLAY
DESCRIPTION:Default Event Notification
X-WR-ALARMUID:45da49a7-9941-4ff9-8b27-b45c5c4c4c39
END:VALARM
END:VEVENT
END:VCALENDAR
--->

Show:

Event title: CalDAV-Sync Test Event
 From 11/19/2013 17:00 to 11/19/2013 17:59 Timezone: Europe/Berlin
=> The date is converted but there is no reason to convert it as in  
the ics file there is:
DTSTART;TZID=Europe/Berlin:20131119T180000
DTEND;TZID=Europe/Berlin:20131119T190000


Now, just do the following modification in the ICS file:
-DTSTART;TZID=Europe/Berlin:20131119T180000
+DTSTART;TZID=Europe/Paris:20131119T180000
-DTEND;TZID=Europe/Berlin:20131119T190000
+DTEND;TZID=Europe/Paris:20131119T190000

(and so keep Europe/Berlin for TZID and X-LIC-LOCATION.)

--->
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//dmfs.org//mimedir.icalendar//EN
BEGIN:VTIMEZONE
TZID:Europe/Berlin
X-LIC-LOCATION:Europe/Berlin
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20131119T180000
DESCRIPTION:Some Description
SUMMARY:CalDAV-Sync Test Event
LOCATION:Some Location
TRANSP:OPAQUE
STATUS:CONFIRMED
DTEND;TZID=Europe/Paris:20131119T190000
LAST-MODIFIED:20131118T133721Z
DTSTAMP:20131118T133721Z
CREATED:20131118T133721Z
UID:d9efd40a-39b5-4d62-9129-83ff649fa1a8
BEGIN:VALARM
TRIGGER;VALUE=DURATION:-PT10M
ACTION:DISPLAY
DESCRIPTION:Default Event Notification
X-WR-ALARMUID:45da49a7-9941-4ff9-8b27-b45c5c4c4c39
END:VALARM
END:VEVENT
END:VCALENDAR
--->

Show:

Event title: CalDAV-Sync Test Event
 From 11/19/2013 18:00 to 11/19/2013 18:59 Timezone: Europe/Paris

Of course, i have tried this two imports tests multiple times for be  
sure of the result.