Time & NTP

Keeping Time in Sync

Accurate time matters for logs, TLS certs, and Kerberos.

CommandPurpose
timedatectlShow/set time, zone, NTP status
timedatectl set-timezone Asia/KolkataSet timezone
timedatectl set-ntp trueEnable network time sync
chronyc sourceschrony NTP sources (RHEL)
date / hwclockSystem / hardware clock
$ timedatectl
               Local time: Mon 2025-01-06 10:00:00 IST
     System clock synchronized: yes
                   NTP service: active
Exam tip: chronyd (RHEL) and systemd-timesyncd (Ubuntu) are the modern NTP daemons - ntpd is legacy.