[tz] [PROPOSED] Merge timezones that are alike since 1970

[Michael H Deckers]

    On 2021-06-02 17:24, John Hawkinson via tz wrote:

> Brian Inglis via tz <tz at iana.org> wrote on Wed,  2 Jun 2021
> at 13:10:34 EDT in <974cf8e1-c2d8-36bf-ec10-8e99ec826956 at SystematicSw.ab.ca>:
>
>> @-67768040609740800  -2147481748 Jan 01 Mon 00:00:00
>>   @67767976233532799   2147483647 Dec 31 Tue 23:59:59
> That range isn't part of GNU date, I don't think. Under OS X, I get a different result.
> For the negative bound:
>
> pb3:xj2 jhawk$ gdate --version
> date (GNU coreutils) 8.30
> ...
> pb3:xj2 jhawk$ gdate -d @-67768040609722801
> gdate: time ‘-67768040609722801’ is out of range
> pb3:xj2 jhawk$ gdate -d @-67768040609722800
> Thu Jan  1 00:00:00 EST -2147481748
> pb3:xj2 jhawk$


     The value you have given,
          1970-01-01 -  67 768 040 609 722 800 seconds,
     is the smallest value of UT for which the EST value
     U - 05 h is representable in struct tm.

     Brian Inglis has given the smallest and largest
     datetimes representable in a struct tm; this shifts
     the range by 5 hours.

     What I find surprising is that the days of the week
     as given by Brian are incorrect: the Gregorian dates
         -2147 481 748-01-01
         +2147 485 548-01-01
     are both Thursdays.

     Michael Deckers.