isso depende da sua localidade.
você precisa verificar LC_TIME mudar first_weekday de 1 (domingo) para 2 (segunda-feira)
eu apenas pesquisei e isso parece um guia bastante abrangente:
Make a copy of your locale file in your home directory
cp /usr/share/i18n/locales/en_US ~/en_US_modified
create a directory "locales"
mkdir ~/locales
open up en_US_modified in an editor, search for the section called "LC_TIME"
look for the line
first_weekday 1
Change the 1 to a 2
Save the file, exit your editor and go back to the terminal
Run this command which will create a directory full of new locale settings inside of the "locales" directory you made in your home directory:
localedef -c -i ~/en_US_modified -f UTF-8 ~/locales/en_US.utf8
- Backup your old locale settings by going to /usr/lib/locale and changing the name of
en_US.utf8
toen_US.utf8_ORIGINAL
- Copy the new en_US.utf8 directory your created in your home directory in the subdir "locales" to
/usr/lib/locale
- Restart your system
Referência: link ; reformatado para superusuário por mim