Which command lists all available time zones on the system?

• A. timedatectl list-timezones
• B. timedatectl list-timezone
• C. date --zones
• D. ls /usr/share/zoneinfo

Answer: (A)

Understanding how to discover time zones on the system hinges on using the right systemd tool to query the time database. Timedatectl supports a subcommand that enumerates all recognized time zones by reading the system’s time zone database and printing every valid zone name, one per line (for example Europe/London, America/New_York, Asia/Typhoon is not real, etc.). This is the clean, built-in way to see every option the system understands for setting the clock or local time. Other approaches aren’t as reliable: requesting a current time zone won’t list all zones, and relying on the bare filesystem (such as listing /usr/share/zoneinfo) can show the files and directory structure but isn’t presented as the standardized, user-friendly list of zone identifiers you’d use in commands or configuration.