The TimeZone in Debian 8 can be changed with just one command.
To list the available timezones, use the command:
timedatectl list-timezones
Simply choose a TimeZone from the list shown, and then use the command to “set” the desired TimeZone. Considering that we have chosen the TimeZone “America/Sao_Paulo”, we use the command:
timedatectl set-timezone America/Sao_Paulo
That’s it!
Use the “date” command to check the change.