Siga os passos (step-by-step):
like a root:
timedatectl list-timezones
Command will show all locales timezones available, ex:
[root@netserver ~]# timedatectl list-timezones | grep Sao
Africa/Sao_Tome
America/Sao_Paulo
To Set SÃO PAULO as Default:
timedatectl set-timezone America/Sao_Paulo