473915 - [timezone data] exporting Asia/Jerusalem daylight ics EXDATE utc time is wrong

Status: RESOLVED DUPLICATE of bug 504299

(Calendar :: Internal Components, defect)

Description

[ybungalobill]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.5) Gecko/2008120122 Firefox/3.0.5
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.18pre) Gecko/20080917 Sunbird/0.9

As I understood after searching for other bugs, you finally have some kind of support for Asia/Jerusalem timezone, but it still doesn't work properly:
The EXDATE field contains the incorrect UTC time. It seems like Sunbird ignores the DST for this field and doesn't apply the time offset. As a result, I can't import it to programs that has support for Asia/Jerusalem timezone, e.g. Google Calendar.


Reproducible: Always

Steps to Reproduce:
1. Create a new calendar with Asia/Jerusalem timezone.
2. Create a repeating event for a year.
3. Delete some occurrences (in winter & summer).
4. Export the calendar in .ICS format.
Actual Results:  
I get:
BEGIN:VCALENDAR
PRODID:-//Mozilla.org/NONSGML Mozilla Calendar V1.1//EN
VERSION:2.0
BEGIN:VTIMEZONE
TZID:Asia/Jerusalem
X-LIC-LOCATION:Asia/Jerusalem
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0200
TZNAME:IST
DTSTART:19700101T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CREATED:20090116T084251Z
LAST-MODIFIED:20090116T084607Z
DTSTAMP:20090116T084631Z
UID:15f67b10-3e7c-461c-816b-0c19af1b6b5a
SUMMARY:Title
RRULE:FREQ=DAILY;INTERVAL=1
EXDATE:20080804T100000Z
EXDATE:20080928T100000Z
EXDATE:20081005T100000Z
EXDATE:20081102T100000Z
EXDATE:20081214T100000Z
EXDATE:20090104T100000Z
EXDATE:20090208T100000Z
EXDATE:20090301T100000Z
EXDATE:20090405T100000Z
EXDATE:20090503T100000Z
DTSTART;TZID=Asia/Jerusalem:20080803T120000
DTEND;TZID=Asia/Jerusalem:20080803T130000
X-MOZ-GENERATION:24
END:VEVENT
END:VCALENDAR


Expected Results:  
Some of the EXDATE fields have to be 110000Z or 090000Z (the correct one of these two, I'm lazy to think).

Comment 1

[gekacheka]

The VTIMEZONE shown above has only STANDARD, no Daylight Saving Time data.

Confirming: that exporting an event with Jerusalem timezone has no Daylight Saving Time data, as shown above (Sunbird 0.9, "Timezone Definitions for Mozilla Calendar 0.1.2008d").

Looking at the ZoneInfo data for Asia/Jerusalem in Zoneinfo 2008d, there is a very long list of data for daylight saving time (seems to change every year).

Using SQLite Manager extension, opening 
Mozilla Sunbird/extensions/[e-mail]/timezones.sqlite
and browsing tzdata to Asia/Jerusalem, clicking "edit selected", and expanding the 'component' field shows that the above timezone with only standard time is all that is in the database.  

Inspecting timezones.sqlite of the latest nightly shows the same result, its Asia/Jerusalem timezone data contains only standard time, no daylight saving time.

It appears the Asia/Jerusalem daylight saving time data is being dropped during the construction of the VTIMEZONE components from the ZoneInfo rules.

Comment 2

[Philipp Kewisch [:Fallen][📱📆]]

This could be the result of a vzic bug or similar. Australia/Perth has similar issues afaik.

Comment 3

[Nathan Rona]

The DST handling for Jersualem causes problem also when reciving invitation for this time-zone. When accepting the invitation the meeting is set one hour earlier than the actual time. 

The DST in Israel 
Start: Last Friday before April 2
End: The Sunday between Rosh Hashana and Yom Kippur (this date is given by the Hebrew lunar-calender).