I’ve read the thread until the end and honestly I was not able to switch Chrome to display dates in logbook in 24H format.
Chrome sends the following in request header:
Accept-Language: en-GB,en;q=0.9,nl;q=0.8
I cannot remove “en” from that list because this is default Chrome language.
In console (opened for HASS website) I get the following:
> window.navigator.language
"en-GB"
> new Intl.DateTimeFormat().resolvedOptions().locale
"en-US"
> new Date().toLocaleTimeString()
"11:15:20 PM"
The only where “en-US” can leak from is that it is a Windows System language (used for Windows interface). The user’s region is set to UK.
The same difficulty with Home Assitant app for Android which does not display history in 24H format. In App Settings one can find the language settings with two choices: “Device Language” and “English (en)”. My device language is “English (United Kingdom)”.
I will appreciate if one succeeded with any above.
P.S. I cannot test Firefox, because Home Assistant UI simply does not work (files with message can’t establish a connection to the server at wss://hass.website/api/websocket in console however network log is error free, probably that is issue 8318).