kazulog@sv1:~$ sudo timedatectl set-timezone UTC
kazulog@sv1:~$ timedatectl
               Local time: Thu 2026-09-10 23:23:24 UTC
           Universal time: Thu 2026-09-10 23:23:24 UTC
                 RTC time: Thu 2026-09-10 23:23:24
                Time zone: UTC (UTC, +0000)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no
kazulog@sv1:~$ date
Thu Sep 10 23:23:24 UTC 2026
kazulog@sv1:~$ ls -l /etc/localtime
lrwxrwxrwx 1 root root 25 Sep 10 23:23 /etc/localtime -> ../usr/share/zoneinfo/UTC
kazulog@sv1:~$ cat /etc/timezone 2>&1
Asia/Tokyo