Sync with ownCloud makes 2 hours late

[mvg]

Hi,

I´m trying to use EssentialPIMProPortable to check if this will syncronise my PC, Laptop an Android-Smartphone with my own ownCloud-server.

If I sync from Portable to ownCloud, all dates are two hours later (ex. 11.30 am instead of 9:30 am).


Michael

[Max]

Hello,
if it is a public service, please tell its name. If not, please tell owncloud version number.

[mvg]

It´s not public. There is ownCloud 5.0.3 installed.

[Nurgotora]

It's an OwnCloud-bug (-error, -anomaly, ..., tested with version 5.0.6): (1) The data sent by EssentialPIM 5.54 with CalDAV is correct. (2) All entries in OwnCloud's database are correct. (3) Only the display in the OwnCloud's calendar is wrong. (4) Even the Edit-Dialog of OwnCloud's calendar shows the correct time. Educated guess: OwnCloud has some bug involving time zones (2 hours hint at GMT vs CEST) in the display routines.

[Nurgotora]

Part 1: Ok, I've to correct myself - and hate to do it

OwnCloud stores all time in UTC (formerly known as GMT). For display in the webinterface, the time is adjusted to the currently set timezone (see attachment). So, e.g. if we're in Brussels, Belgium, (and have configured that in Owncloud) we have CET with daylight saving time (CEST) and are therefore UTC+02:00.

An event at 21:00 CEST is therefore stored as 19:00 in the database:
BEGIN:VCALENDAR
VERSION:2.0
PRODID:ownCloud Calendar
BEGIN:VEVENT
CREATED;VALUE=DATE-TIME:20130612T110732Z
UID:573d744eb4
LAST-MODIFIED;VALUE=DATE-TIME:20130612T110732Z
DTSTAMP;VALUE=DATE-TIME:20130612T110732Z
SUMMARY:Test3
DTSTART;VALUE=DATE-TIME:20130612T190000Z
DTEND;VALUE=DATE-TIME:20130612T193000Z
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR

and shown as 21:00 in the Calendar. If you change the timezone to London (in the summer it's UTC+01:00), the event will show (after you've reloaded the calendar-page) at 20:00.

Part 2: And now for EssentialPIM -> CalDAV -> Owncloud and the magically added 2 hours: In fact a bug in EssentialPIM

EssentialPIM transmits the time as it has it (21:00):
"DTSTART:20130612T210000"
and wrongly does not make use of one of the two methods specified in rfc2445, section-4.2.19:
A) Either transmit UTC (EssentialPIM should, in our case, substract -02:00 from 21:00)
B) or include the TZID-parameter ("DTSTART;TZID=CENTRAL-EUROPE:20130612T210000")
OwnCloud therefore interpretes the time as UTC, stores it as such in the database and shows, in our example, corrected for UTC+02:00): 23:00

Part 3: The ominous "Z" at the end of the "DTSTART;VALUE=DATE-TIME:20130612T190000Z"
see: rfc2445, section-4.3.5
As mvg an I have noted, the edit-dialog of OwnCloud's calendar shows (for events coming from EssentialPIM) the time stored in the database (21:00), even so the Calender itself shows 23:00. This is because EssentialPIM transmits the time in the form "DTSTART:20130612T210000" (without that "Z" at the end). If EssentialPIM would add that "Z" at the end, both calendar and its edit-dialog would (correctly) show "23:00".

Conclusion
EssentialPIM should transmit UTC in all CalDAV (and probably CardDAV, too) data in the form

DTSTART;VALUE=DATE-TIME:20130612T190000Z

Note for the developers: This is probably much easier and more reliable, as the TZID is not only specified rather complicated in rfc2445 but also tied to an even more complicately specified "VTIMEZONE" calendar component...

It would be great if this could make it into 5.55

===============================

[Nurgotora]

Cool,

as I can just saw (while checking Umlaute and line breaks in CalDav), this has been fixed. An 18:00 to 18:30 (CEST) event is now transmitted (16:00-16:30) UTC with the 'Z' at the end:

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VEVENT
SUMMARY:Test 3
DTEND:20130614T163000Z
DTSTART:20130614T160000Z
DTSTAMP:20130614T123246
UID:20130614T123246707521.ics
SEQUENCE:1
END:VEVENT
END:VCALENDAR

Fine!

[Max]

mvg, can you confirm it is fixed in 5.55?