We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Logic for determining the date/time format

  • 2 replies
  • 1 has this problem
  • 3 views
  • Last reply by palswim

more options

In my quest to display my messages with the ISO date format (yyyy-mm-dd), I determined that I needed to set a locale that would have the date format I desired, whether an existing locale or creating a custom locale.

I had read that the en_DK locale might provide what I wanted, and a quick call to LC_TIME=en_DK date +'%x' verified that it output the ISO-standard format. However, starting Thunderbird (LC_TIME=en_DK.UTF-8 gtk-launch thunderbird), Thunderbird displayed dates for my messages in a different format. But, when I started Thunderbird with the sv_SE locale (LC_TIME=sv_SE.UTF-8 gtk-launch thunderbird), Thunderbird did display the dates in the ISO format. Where does Thunderbird retrieve its date format, and why does it differ from date +'%x'?

In my quest to display my messages with the ISO date format (<i>yyyy-mm-dd</i>), I determined that I needed to set a locale that would have the date format I desired, whether an existing locale or creating a custom locale. I had read that [https://unix.stackexchange.com/q/62316/13308 the <b>en_DK</b> locale might provide what I wanted], and a quick call to <code>LC_TIME=en_DK date +'%x'</code> verified that it output the ISO-standard format. However, starting Thunderbird (<code>LC_TIME=en_DK.UTF-8 gtk-launch thunderbird</code>), Thunderbird displayed dates for my messages in a different format. But, when I started Thunderbird with the <b>sv_SE</b> locale (<code>LC_TIME=sv_SE.UTF-8 gtk-launch thunderbird</code>), Thunderbird did display the dates in the ISO format. Where does Thunderbird retrieve its date format, and why does it differ from <code>date +'%x'</code>?

Modified by palswim

All Replies (2)

more options

Try checking the setting in Edit > preferences > advanced > general.

more options

Matt said

Try checking the setting in Edit > preferences > advanced > general.

You mean the Date and Time Formatting setting, with the options to choose between Application locale and Regional settings locale?

That setting did switch locales upon restart, but using the en_DK locale, Thunderbird still formatted the date differently than LC_TIME=en_DK date +'%x'.