[Bug]: Dates where moment.js is used seem to take locale instead of language

[jancborchardt]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Dates where moment.js is used seem to take locale instead of language.

Date in German in link previews:

Mixed English and German in Talk chat:

Steps to reproduce

1. Have English as language but German as locale
2. Add a link in Talk or Text, or look at a relative date
3. It will be German

Expected behavior

The date should consider the language for its language, and the locale only for the format.
Is this possible with Moment.js? cc @juliushaertl @nickvergessen

Installation method

None

Nextcloud Server version

master

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[nickvergessen]

I had a fix attempt back in 2019
#14784

Duplicate of #15457

[nickvergessen]

Adding that one to your board for tracking