Well at least the datetime library would be a perfectly reasonable place to handle leap seconds. The place that outputs the timestamp to a human readable format wouldn’t at all be that hard pressed to add a second when printing out the local time with timezone considered. It really wouldn’t add that much complexity.

Could you imagine if anyone was stupid enough to think the right place to handle such a thing was the internal counter of seconds rather than the datetime library though? Ha! That’d be ridiculous right! Imagine all the bugs if someone put something that’s only relevant to local timezone time printing there! It’d cause so many unexpected bugs!