[tz] tzdata isstd question

[Paul Eggert]

On 10/29/2015 12:53 PM, Ken Murchison wrote:
> 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
>
>
> I'm wondering why the transition on Feb 9, 1942 isn't flagged as being 
> observed at standard time in the compiled tzfile.

Sorry, I must be missing something, but I am not following the question. 
For that absolute transition, there's no difference between 02:00 
standard time, 03:00 local time, and 08:00 UTC; they're all the same 
thing, and the "s" in "2:00s" is purely for convenience in the source data.