[tz] Unacceptable recent changes [wasRe: [PATCH 2/4] Move obsolescent Americas entries to 'backward'.]

[Stephen Colebourne]

On 26 August 2013 18:16, Paul Eggert <eggert at cs.ucla.edu> wrote:
>  # Shanks & Pottenger say that Atikokan has agreed with Rainy River
>  # ever since standard time was introduced, but the information from
>  # McKinnon sounds more authoritative.  For now, assume that Atikokan
>  # switched to EST immediately after WWII era daylight saving time
>  # ended.  This matches the old (less-populous) America/Coral_Harbour
>  # entry since our cutoff date of 1970, so we can move
> -# America/Coral_Harbour to the 'backward' file.
> +# America/Coral_Harbour to the 'backward' file.  And Atikokan itself
> +# is the same as America/Panama since 1970, so we can move
> +# America/Atikokan to the 'backward' file as well.
> -Zone America/Atikokan  -6:06:28 -      LMT     1895
> -                       -6:00   Canada  C%sT    1940 Sep 29
> -                       -6:00   1:00    CDT     1942 Feb  9 2:00s
> -                       -6:00   Canada  C%sT    1945 Sep 30 2:00
> -                       -5:00   -       EST

So if I understand correctly, all changes to Atikokan before 1970 have
just been lost?

And they are supposed to use Panama from now on?


Here is what JSR-310 can tell us about the two sets of rules:

America/Atikokan
Transition[Gap at 1895-01-01T00:00-06:06:28 to -06:00]
Transition[Gap at 1918-04-14T02:00-06:00 to -05:00]
Transition[Overlap at 1918-10-27T02:00-05:00 to -06:00]
Transition[Gap at 1940-09-29T00:00-06:00 to -05:00]

America/Panama
Transition[Overlap at 1890-01-01T00:00-05:18:08 to -05:19:36]
Transition[Gap at 1908-04-22T00:00-05:19:36 to -05:00]

Merging these is clearly utterly RIDICULOUS.

They contain completely different data, and the 1970 argument simply
won't wash. Many users will have stored data in databases or other
long term storage that refers to these time-zones being made obsolete.
When they read the data back, they will get completely different times
for historic events - utterly unacceptable.

More broadly, no one can pretend that the IDs we use are meaningless.
Whether they should or should not have been created this way is not
relevent - what matters is that these IDs are meningful and getting
rid of them would be a disaster. The IDs are clearly localized, and
they have a huge and longstanding usage globally. Panama is nowhere
near Atikokan, nor would any reasonable user connect the two.

Paul, you need to STOP NOW.

You need to reverse the vast majority of your recent changes. Focus on
actual changes happening in 2013. Keep the rest of the database
totally and utterly stable. And just accept that there is a measure of
politics incumbent in time-zones.

NONE of these changes should be happening. STABILITY is vital.

Stephen