Why might `date` be showing 12h format?

Question

I've always seen 24h time shown in the date output. But for some reason, my Debian-based machine is now showing 12h time format:

$ date
Fri 10 Jun 2022 06:16:47 PM IDT

$ LC_TIME=en_IL.UTF-8 date
Fri 10 Jun 2022 06:17:00 PM IDT

$ LC_ALL=en_IL.UTF-8 date
Fri 10 Jun 2022 18:17:05 IDT

I don't think that I changed anything relevant lately.

$ grep LC_ ~/.bashrc
export LC_TIME="en_DK.UTF-8"
$ grep LC_ ~/.profile 
$ locale
LANG=en_IL.UTF-8
LANGUAGE=en_US
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=en_US.UTF-8

What else should I check or configure?

My goal would be to have these features:

• 24h time format
• YYYY-MM-DD date format
• Week starts on Sunday
• Text in English
• Beer served below room temp, but not at refrigerator levels of cold
• UTF-8 encoding

In these applications:

• Bash commands, such as date.
• Anki
• Firefox
• Thunderbird
• KeepassXC
• LibreOffice
• KDE Applications, such as Okular and Dolphin
• Gnome applications

My setup is KDE 5.18.8 on Ubuntu 20.04.4 LTS. I have no problem updating to 22.04 if necessary.

Answer 1

Your times are shown in 12h format because of this setting:

LC_ALL=en_US.UTF-8

This overrides your LC_TIME setting, and produces 12h times.

Presumably something changed recently to produce this LC_ALL setting in your environment. grep -r LC_ALL /etc should tell you where.

See also What is the difference between LANG=C and LC_ALL=C? for context on LANG v. LC_ALL.