piped uses jalali dates only when language of firefox is set to Persian but no when content language is set to persian

[rezad1393]

Official Instance

• The bug is reproducible on the official hosted instance, or is API-related.

Describe the bug

I use firefox.
today I set my "Choose your preferred language for displaying pages" to persian-iran and perisan and then put them at the top of english.

this causes many sites to use persian language. for example google search.
also this causes google search to show dates in jalai (persian) calendar.
youtube shows UI words in persian and date are still Gregorian.

then I set the firefox UI language in persian "Choose the languages used to display menus, messages, and notifications from Firefox." and then restarted.
that doesnt have any other effect on other sites but for piped.video it causes the dates to be shown in persian(jalali) calendar

this has two issues.

first:
the change to dates in jalali should have happened with content language not with firefox UI language.

second and weirder one:
how does piped.video finds out what my firefox UI language is?

To Reproduce

use firefox.
I set "Choose your preferred language for displaying pages" to persian-iran and perisan and then put them at the top of english.

this causes many sites to use persian language. for example google search.
also this causes google search to show dates in jalai (persian) calendar.
youtube shows UI words in persian BUT date are still Gregorian.

I set the firefox UI language in persian "Choose the languages used to display menus, messages, and notifications from Firefox." and then restart.

go top piped.video and open a video page.
date are shown in jalali.

Expected behavior

the first part (setting content language) should have set the dates.

Logs/Errors

No response

Browser, and OS with Version.

firefox 127.0.2 (64-bit) on arch

Additional context

No response