SC-45(2)—Secondary Authoritative Time Source
>Control Description
a. Identify a secondary authoritative time source that is in a different geographic region than the primary authoritative time source; and b. Synchronize the internal system clocks to the secondary authoritative time source if the primary authoritative time source is unavailable.
>Supplemental Guidance
It may be necessary to employ geolocation information to determine that the secondary authoritative time source is in a different geographic region.