Are the critiques in "All the things I hate about Python" valid?

[Ian Kelly]

On Mon, Feb 26, 2018 at 8:55 PM, Ian Kelly <ian.g.kelly at gmail.com> wrote:
> On Mon, Feb 26, 2018 at 8:09 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> Yes you did: "the last second of every year" is always 23:59:59 of 31st
>> December, and it is always the same time and date "every year".
>
> Except when it's 23:59:60 or 23:59:61 (which hasn't yet happened but could).

Actually, after doing some reading on the subject just now, I learned
that double leap seconds don't actually exist! They were accidentally
invented by the drafters of the ANSI C standard and later propagated
to the POSIX standard and the ANSI SQL standard.

https://www.ucolick.org/~sla/leapsecs/timescales.html#UTC

So the actual last second of the year must always be one of 23:59:58,
23:59:59 or 23:59:60.

(Hint: although we've never had a negative leap second to date, don't
schedule your database update for 23:59:59 if you want to ensure that
it actually happens.)