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by WalterBright 3717 days ago
> Operating systems kind of suck at it.

Sure, but they usually have more resources than programming language teams. Consider all the programming languages on your machine. Can you trust they all did the timezone, with all its nuances, correctly?

Consider something simpler - the trig functions. I've noticed time after time that many language libraries get it wrong, and this is with decades of development. Errors are usually in the form of precision that is lower than it should be, and poor handling of special values like NaN and infinity.

The situation with that is so erratic that with the D programming language we'd write our own trig implementations rather than use the C library ones.
1 comments
laut 3716 days ago
They might have more resources, but they also have constraints. For instance a tzdata update was just released yesterday. Apple has a lot of resources but I don't see an updated from them today on iOS nor Mac OS X. Elixir tzdata automatically updates to the new version.

Does Apple even have resources that work on tzdata code? Or do they just use open source code?

I wrote more about the issue here: http://www.creativedeletion.com/2015/12/03/timezone-updates-...

In particular for Elixir I trust the time zone data from Tzdata more than for any other language, mostly because I know it is designed to have up to date data. (And well, I know the code because I wrote it myself.)

Even if a system is good in many ways it does not matter if the data is not up to date.

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