Thank you Greg for the clarification. I find your third link https://wiki.debian.org/DotFiles very worth reading.
Regards, Jörg Greg Wooledge wrote on 05/06/2019 14:52: > On Wed, Jun 05, 2019 at 11:18:55AM +0200, Jörg-Volker Peetz wrote: >> As user of thunderbird you best set the environment variable LC_TIME in your >> profile, e.g. via ~/.bash_profile . Check it with the command >> >> $ locale >> >> You have to log out (from desktop and from computer) before changes in >> .bash_profile get applied. > > For the record, .bash_profile is only read by login shells, so your > suggestion only works for situations where one logs in with a shell > (Linux virtual console logins or ssh), not where one logs in with a > graphical Display Manager. > > See also: > https://wiki.debian.org/Xsession > https://wiki.debian.org/EnvironmentVariables > https://wiki.debian.org/DotFiles > >