Date format changed in 60.2.1
Ubuntu 16.04LTS, 64 bit. Thunderbird 60.2.1. Locale is en_AU, standard from distro. So time format is 24hr ("%T") Previously, the date column in folder listings showed 24 hour time. In 60.2.1, it is using "3:24pm" style 12 hour format, which is not what I want. Nor does it conform to the documentation I can find, which refers to using system formats. There is also something that changed in the formatting of dates, which I can't put my finger on.
ప్రత్యుత్తరాలన్నీ (2)
Thunderbird 60 has an application locale or a system locale setting.
In Linux that would be edit preferences > advanced general. I suggest you check it. BTW the default system date for the AU space is 12 hour AM/PM. So my guess is you are not set to "Regional settings"
The setting within Thunderbird makes no difference, but it was on "regional" anyway. Application locale is en_GB, Regional is en_AU. And yes, I am restarting Thunderbird after each change. Also, the system default setting is 24 hour, as shown by 'date +%X', so your BTW is inaccurate.