NIST 800-53v5 - SC-45.1 - Synchronization with Authoritative Time Source
Compare the internal system clocks [ Assignment: frequency ] with ; and
Synchronize the internal system clocks to the authoritative time source when the time difference is greater than [ Assignment: time period ].
Guidance
Synchronization of internal system clocks with an authoritative source provides uniformity of time stamps for systems with multiple system clocks and systems connected over a network.