In addition to what others have mentioned, if these systems are to
perform route origin validation (ROV), an accurate notion of time would
be desirable. From section 6 in IETF RFC 7115 / BCP 185 - Origin
Validation Operation Based on the Resource Public Key Infrastructure
As a router must evaluate certificates and ROAs that are time
dependent, routers' clocks MUST be correct to a tolerance of
approximately an hour.