On Sun, Nov 27, 2016 at 12:44 PM, Oren Tirosh <orent@hishome.net> wrote:

The "gaps" in conversion from Caesia Standard Time to UTC all correspond to UTC Leap Seconds. It is well-known that gaps at one end of a timezone conversion correspond to "folds" at the other end - a period that occurs twice. Until recently, there was no support for folds in the datetime library of the Python language (Caesians are avid Pythonistas). Now that PEP495 has been implemented they are keen to check how well the datetime library interoperates with their unusual (yet completely well-formed and valid) time zone definition.

Can you help them?

I am not sure how serious your post is, but I've been toying with an idea that UTC y-m-d:23:59:*60* should be represented in Python as datetime(y, m, d, 23, 59, *59*, fold=*1*). This would allow one to implement Olson's "right" timezones - a timekeeping scheme where time_t is at a fixed offset of TAI and UTC has a second-wide "fold" on every positive leap second.