request: convert times to users local timezones

[zachary-D]

Checklist

• I'm reporting a feature request
• I've verified that I'm running youtube-dl version 2019.08.13
• I've searched the bugtracker for similar feature requests including closed ones

Description

I'd like youtube-dl to convert upload dates to the users current timezone when substituting for '%(upload_date)s' in output filenames. Twitch in particular (and presumably many more) return their timestamps in UTC, and youtube-dl does not convert them before substitution which leads to the upload date being inconsistent in different timezones. In my case this results in evening streams being labelled as the day after, while morning streams are marked labelled properly. I originally thought this was a bug ( #22173 ), more specific examples of this behavior are available there. Thank you for considering my request!

[chuckn408]

What would have to happen is basically a fork of upload_date to upload_date_local.
upload_date_local would have to::
-get timezone of file
-get timezone of pc
-some arithmetic
-append the adjusted difference between the two as the title

A quick search showed something promising:

from dateutil.tz import tzlocal
datetime.now(tzlocal())

I'll see if I can whip something up in the next day or so.

[dstftw]

This will not work since you don't know the original timezone in general.

[zachary-D]

I meant the timezone of the downloader, not the recorder

[zachary-D]

To clarify, I was looking to have the date twitch reports (which is in UTC) to the downloader's current timezone.