The correct timezone affects more than the clock on your screen. It drives cron job scheduling, systemd timer execution, log file timestamps, database record timing, and SSL certificate validity checks. A mismatched timezone can cause scheduled jobs to fire at the wrong hour and make log timestamps impossible to match with real-world events.
This guide shows how to change timezone on Ubuntu using the timedatectl command (the recommended approach for servers and remote machines) and through the graphical Date & Time settings on desktop systems. The steps apply to all current Ubuntu releases including 24.04 and 26.04.
<strong>Prerequisite:</strong> Only the root user or a user with sudo access can change the system timezone.
Check the Current Timezone Before You Change It
Run timedatectl with no arguments to see the active timezone and clock status:
bashtimedatectl
Sample output:
Local time:...