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".