FW: Europe/Paris timezone bug

[LIVINGSTON Alex]

Jason, Rodrigo, and others:

I at first misunderstood Jason's explanation because he wrote 
"...Daylight saving goes into effect..." when what he meant was 
"...daylight saving goes out of effect..." or "...daylight-saving time 
ends...", and I then didn't look at the dates in the following output.

Rodrigo's explanation is correct, but it overlooks one thing: if the 
device's clock is set to a time between 02:00 and 03:00 on the morning 
that daylight saving ends, the behaviour described implies that the 
device regards the time it is set to as being the first occurrence of 
that time that night (as all times between 02:00 and 03:00 occur twice 
on that night). What determines that?

If, as I first imagined, the time of a device is set to 02:14 on the 
morning daylight saving _starts_, a time that does not occur, what 
happens then?

Alex

On Friday, Oct 31, 2003, at 01:47 Australia/Sydney, Rodrigo Severo 
wrote:

> Jason,
>
>
> I am not sure I understood your problem but let me try to help you.
>
>> There appears to be a bug in the timezone libraries(i've tested 
>> against localtime.c	7.76) when dealing with Daylight Saving Time and 
>> the France timezone. Daylight saving goes into effect at 3:00am 
>> instead of 2:00am. Below I have attached simple test case.
>>
> I am not sure why do you think Daylight saving should end its effect 
> at 2:00am localtime instead of 3:00am localtime as it's currently 
> defined in the zoneinfo file but AFAICS, it's not a library bug, it 
> might be a zoneinfo definition bug:
>
> Rule    EU      1996    max     -       Oct     lastSun  1:00u  0      
>  -
>
> The above rule states that the daylight saving ends at the last sunday 
> of october 1:00 UTC time.
>
> The Europe/Paris zone defines that Paris is one hour ahead of UTC 
> outside daylight saving time, or 2 hours during daylight saving time 
> so only at 3:00 local time (which is 1:00 UTC time) the daylight 
> saving should end. Which is what is happening, isn't it?
>
> As far as as can understand, there is no library bug. There might be a 
> zoneinfo bug if this (daylight saving ending only at 3:00am localtime) 
> isn't what should happen.
>
>
> Regards,
>
> Rodrigo Severo
>
>> This is the output of the test I ran on both Mac(10.2.8) and PalmSim
>>
>> bash-2.05a$ TZ="Europe/Paris" ./a.out
>> when = 0x3f9b0e44 is_dst = 1 zone = CEST Sun Oct 26 01:59:00 2003 
>> when =
>> 0x3f9b0e80 is_dst = 1 zone = CEST Sun Oct 26 02:00:00 2003 when = 
>> 0x3f9b11c8
>> is_dst = 1 zone = CEST Sun Oct 26 02:14:00 2003 when = 0x3f9b2014 
>> is_dst = 0
>> zone = CET Sun Oct 26 02:15:00 2003
>>
>> You will notice that the difference between 02:14:00 and 02:15:00 is 
>> 3660 which is 61 minutes. If you set the device to 2:14 and wait 46 
>> minutes it will change the time back to 02:00.
>>
>> There should be no difference in setting the time to 02:00, 02:14, or 
>> 02:15 since anytime after 02:00 should fall outside of Daylight 
>> Saving Time on this date.
>>
>> Thanks,
>> --jason
>>
>
>> -- 
>>
> ----------------------------------------------------
> Rodrigo Severo
> Fábrica de Idéias
> Fone: +55(61)321 1357
> Fax: +55(61)223 1712
> SBS - Quadra 2 - Ed. Empire Center - Sala 1301
> Brasília/DF - Brasil
> CEP: 70.070-904
> ----------------------------------------------------
>
>