Decouple time/date format from language selection

[Janub]

I think it would be very useful, if you could select your preferred date and time format independently of the UI language. With the current system, selecting English as the UI language automatically also results in a 12h time format and the american MM/DD/YYYY date format.
Ideally you could chose a date and time format on your user settings page, where Theme, Timezone, etc. are configured as well.

[jbtronics]

In principle this is already possible, by manually choosing the right locale.

The en locale automatically defaults to something like en_US so its english with american datetime format. However in principle you can choose any country format you want for that. For example en_DE gives you english language with german datetime format (therefore DD/MM/YYYY and 24h).

There is currently just no way to navigate to that locale via the UI I think. However you can easily access it by modify the URL yourself (just replace the /en/ part with /en_DE/).

For example https://demo.part-db.de/en_DE/log/18567/details shows the dates in german format.
The locale should stay at subsequent navigations from that page.

[Janub]

I tried your suggestion and it mostly solves the issue for me. There are, however, two minor problems:

1. The date is shown as DD/MM/YYYY with en_DE, but with just de it is shown as DD.MM.YYYY. It is not a big issue, but still interesting to see as apparently not all of the date formatting is done in the same way.
2. Some string translations are missing when using the en_DE locale. So far I only noticed the search placeholder "search.placeholder" and the indicator for adding a new catecory/footprint/etc. "entity.select.group.not_added_to_DB"
   Overall I would still love to have the option to choose date format, time format, language (and perhaps decimal separator) as a user setting, but the manual choice of locale is a good workaround for now.

[jbtronics]

2. Some string translations are missing when using the en_DE locale. So far I only noticed the search placeholder "search.placeholder" and the indicator for adding a new catecory/footprint/etc. "entity.select.group.not_added_to_DB"

This is now fixed with the latest commit