398323 - New Zealand Daylight Savings Dates Incorrect

Status: RESOLVED WORKSFORME

(Calendar :: General, defect)

Description

[ashtonaut]

User-Agent:       Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506)
Build Identifier: 0.5 (2007062404)

It appears the Daylight Savings dates for New Zealand have not been updated to the current dates. From NZ Internal Affairs website:

It now commences from the last Sunday in September, when 2.00am becomes 3.00am, and ends on the first Sunday in April the following year, when 3.00am becomes 2.00am.

Currently, all events between the new start date (last Sunday in September) and the old start date (first Sunday in October) are displayed out by one hour. Events after the old start date are displayed correctly. I am using the correct timezone (Pacific/Auckland), and my OS has corerctly updated for DST.

Reproducible: Always

Steps to Reproduce:
1. Set OS timezone to New Zealand, and Lightning timezone to Pacific/Auckland.
2. Create an event between 30 September 2007 - 6  October 2007.
Actual Results:  
Event is displayed in the calendar one hour too early. If the event is edited, the correct time is displayed in the dialogue box.

Expected Results:  
Correct time should be displayed in the calendar view.

I assume this bug is caused by the Lightning DST information not having been updated to include the changes made to NZ DST in 2007.

Comment 1

[Stefan Sitter [:ssitter]]

Current definition as (of 29-Jan-2007) in Sunbird 0.7 is:

    BEGIN:VTIMEZONE
    TZID:/mozilla.org/20070129_1/Pacific/Auckland
    X-LIC-LOCATION:Pacific/Auckland
    BEGIN:STANDARD
    TZOFFSETFROM:+1300
    TZOFFSETTO:+1200
    TZNAME:NZST
    DTSTART:19700315T030000
    RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=3SU;BYMONTH=3
    END:STANDARD
    BEGIN:DAYLIGHT
    TZOFFSETFROM:+1200
    TZOFFSETTO:+1300
    TZNAME:NZDT
    DTSTART:19701004T020000
    RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1SU;BYMONTH=10
    END:DAYLIGHT
    END:VTIMEZONE

Comment 2

[ashtonaut]

I'm not intimately familiar with the format of this definition, but it would appear to me that this is the old DST information. The new end date (line 9) would become:

RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1SU;BYMONTH=4

I'm not sure about the start date (line 16) as it is specified as the "last Sunday in September" - this could be BYDAY=4SU or BYDAY=5SU...

Comment 3

[Bas van den Bosch]

From 
http://www.dia.govt.nz/diawebsite.nsf/wpg_URL/Services-Daylight-Saving-Index 
it's the last sunday of september, so:
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=9
(or should BYMONTH be 10?)
added blocking 0.7, this is a minor change but could be a big annoyance...

Comment 4

[Bas van den Bosch]

from the ietf logs it should be BYMONTH=9, last sunday of september...
http://www3.ietf.org/meetings/ietf-logs/calsify/2006-10-03.html

Comment 6

[Stefan Sitter [:ssitter]]

The real issue is: What other timezones use NZ time and need to be updated too? What other non-NZ timezones changed too since the timezone database update on 29-Jan-2007? 

Do we want to do a timezone database update that short before the 0.7 release? The issues seen will disappear in 4 days when the Lightning internal timezone switches to DST too. Once Bug 314339 is fixed and we have a upgradeable timezone database this should be easier I hope.

Comment 7

[Omar Bajraszewski]

(In reply to comment #6)
> The real issue is: What other timezones use NZ time and need to be updated too?

I've found some information that can be useful:
http://support.microsoft.com/kb/931836
http://webexhibits.org/daylightsaving/g.html

Comment 8

[cmtalbert]

When I complete 314339, I'm going to upgrade us to the latest Olson database.  The new Olson database that I have been using for that testing already has this change in it.  (Olson version 2007g)

Thanks for bringing this to our attention.

Comment 9

[cmtalbert]

And I apologize in advance for the inconvenience you're going to experience from now until October w.r.t. the calendar doing weird things with your dates.

Comment 10

[ashtonaut]

The minor inconvenience is tolerable, as mentioned this only affects events this week (1 Oct - 6 Oct). As long as this is fixed in one way or another before the end of Daylight Savings in NZ (April 2008, when the difference is two weeks), it's not a showstopper.

From what I can see it seems only New Zealand and the Chatham Islands are affected by this change:

http://www.statoids.com/tnz.html

Comment 11

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

helping to mass reassign from requesting blocking‑calendar0.7 to wanted‑calendar0.8.

Comment 12

[Simon Paquet [:sipaq]]

This will be handled by the blocking bug 314339, therefore no wanted0.8-status is needed.

Comment 13

[Stefan Sitter [:ssitter]]

Please retest with a recent 0.8pre nightly build if the internal timezone for New Zealand is now correct after the checkin for Bug 410931.

Comment 14

[Martin Schröder [:mschroeder]]

After having a look at our timezone database we should have the latest valid timezone data for "Pacific/Auckland". -> Resolving FIXED, but feel free to re-open if you can still reproduce this issue.

Comment 15

[Philipp Kewisch [:Fallen] [:📆][:🧩]]

These bugs are likely targeted at Lightning 1.0b1, not Lightning 1.0. If this change was done in error, please adjust the target milestone to its correct value. To filter on this bugspam, you can use "lightning-10-target-move".