Change the format of the date column in Thunderbird

Assuming I'm reading the source code correctly, this isn't currently possible. The date format is configurable, and can be turned off altogether as noted in the wiki article you referenced, but the time is always shown according to the computer's locale (without seconds).

If you're up for fiddling with the source code, look at the end of the FetchDate function in mailnews/base/src/nsMsgDBView.cpp. You'll need to change kTimeFormatNoSeconds to something else (see the Date and Time Formatting functions page for details).

Update. There is another addon: Super Date Format.

1. Install Super Date Format addon
2. Go to Preferences
3. Go to Date Format
4. Insert %Y.%m.%d %H:%M into Date Format
5. Go to Date Format Preferences
6. Check Enable on Date column
7. Check Enable on Received column
8. Restart Thunderbird

Now all messages can by sorted by date no matter how old. The new format only cosists of numbers.

Please check new feature available after TB 60+

An option under "Tools > Options, Advanced, General" now allows to select whether date/time display will follow the application locale (adjusted by operating system's format settings for that locale) or the locale selected in the operating system's regional settings. In other words, an US English Thunderbird can use, for example, German formats.

https://www.thunderbird.net/en-US/thunderbird/60.0/releasenotes/