[tz] South Sudan to change time zone?

Paul Eggert eggert at cs.ucla.edu
Mon Feb 8 08:45:49 UTC 2021

On 2/7/21 10:16 AM, Hayo Schmidt wrote:

> you created a new
> edge case by defining 00:00 of a day and then shifting back the date by
> one day (and 23 hours forward).

This sort of edge case is not new to Africa/Juba. For example, it 
occurred on 2020-03-22 at 00:00 in America/Asuncion, and is scheduled to 
occur again on 2021-03-28 at 00:00 at the same location.

> A datum could have been created when reaching the first time exactly
> 00:00:00.000.

This is modeled in tzdb by the clock ticking 23:59:59.999999999 (as many 
9s as you like) followed by 23:00:00.000000000 (the same number of 0s). 
That is, all the timestamps from 23:00:00.000000000 through 
23:59:59.999999999 occur twice, but 00:00:00.000000000 the next day 
occurs only once.

In this sense, there's no difference between a transition at 24:00, and 
one at 02:00.

You can seem more details by running the command "zdump -v Africa/Juba".

More information about the tz mailing list