Use standard library for date and time when possible

[JuneStepp]

pytz dependency is removed. isodate is still needed for ISO durations and missing features in Python's ISO datetime parser.

closes #1442, closes #1420

[Mogost]

This code will not work in Python 3.8
But currently pyproject.toml has

requires-python = ">=3.8"

So python should be 3.8 should be dropped here or this PR should be dependent on another PR with dropping the mentioned support.

[JuneStepp]

This code will not work in Python 3.8 But currently pyproject.toml has

requires-python = ">=3.8"

So python should be 3.8 should be dropped here or this PR should be dependent on another PR with dropping the mentioned support.

What part doesn't work on 3.8? I'm not using zoneinfo, because it wasn't actually necessary.

[Mogost]

@JuneStepp sorry I was wrong.

[silasserner]

Are these changes ready to be merged?
Would be great to get rid of Pytz.

[JuneStepp]

Are these changes ready to be merged? Would be great to get rid of Pytz.

Ya. They have been.

[silasserner]

They have not been merged yet.
This commit is still just open and not merged.
And I 've checked the code and it still uses pytz.

[JuneStepp]

They have not been merged yet. This commit is still just open and not merged. And I 've checked the code and it still uses pytz.

Yes. This code has been ready to be merged a long time but has not been.

[silasserner]

They have not been merged yet. This commit is still just open and not merged. And I 've checked the code and it still uses pytz.

Yes. This code has been ready to be merged a long time but has not been.

I'm fairly new as a commenter.
Do you know how to poke the maintainer?

[JuneStepp]

I'm fairly new as a commenter. Do you know how to poke the maintainer?

You would do @<their username> at the beginning of your message, but that probably wouldn't be helpful here. There are many PRs that need looking at, since this repo has had very limited maintenance for a while.

[silasserner]

I give it a shot

@mvantellingen This pull request looks ready to be merged into main.
Pytz is overdue and can easily be removed with this.

[silasserner]

@mvantellingen Thanks for merging, any chance there will be a package update on pypi?