Hi,
Some aspects of locales and timestamp formatting have been discussed
recently. After upgrade to Debian 13 trixie I faced Firefox behavior
rather surprising for me.
In UI elements I have UK dd/mm/YYYY (not mm/dd/YYYY, expected however)
date and 12 hours am/pm US time format (that I prefer to avoid). My
impression is that LANGUAGE environment vairable has higher priority
than LANG and LC_TIME namely for time (that is unexpected), but not for
date. Usually I report Firefox bugs to the upstream bug tracker, but due
to bookworm vs. trixie difference this time I suspect a Debian-specific
issue. Can anybody confirm discrepancy?
When firefox is not running (or use another profile)
LANG=en_GB.UTF-8 LANGUAGE=en_US:en firefox-esr
Open history [Ctrl+Shift+H] and enable the most recent visit column.
What are date format and time format?
I admit, my setup is a bit peculiar and not really consistent, but so
far I was happy with it. I am running stripped version of plasma desktop
and some recommended packages are missed. I am interested if the issue
is reproducible for other DEs. I would not be surprised if it is related
to some new D-Bus service or a library.
I do not like inconsistency between date and time formatting. Perhaps
the issue may be reproduced with other locales as well. Check that
specified locales are present in output of
locale -a
otherwise enable them using "dpkg-reconfigure locales" or by editing of
/etc/locale-gen with following locale-gen. Notice that LANGUAGE should
contain list of languages, not locales, so do not add ".UTF-8" there.
My experience is that locale packages like firefox-esr-l10n-en-gb are
not important.
Notice that web pages are another story than browser UI. You may test a
HTML file like
<!DOCTYPE html>
<input type="datetime-local" value="2026-01-06T17:12">
but it is more complicated and result may be affected by e.g.
navigator.languages and intl.regional_prefs.use_os_locales.
My native language is not English, but to have messages and menu entries
that can be directly put into search queries at first I set
LANG=en_US.UTF-8. Later I realized that US datetime format is
inconvenient for me and I changed it to LANG=en_GB.UTF-8. I have not
update LANGUAGE, so I have some sort of inconsistency. Perhaps I should
set to en_GB.UTF-8 just LC_TIME, but in trixie it is partially
disregarded by Fiurefox.
I will be grateful if somebody confirms that inconsistent time vs. date
formatting with disregarding of LC_TIME and LANG in presence of LANGUAGE
may be reproduced in trixie, but not in bookworm.
