A contractor has retained you to assess compliance with CMMC practices as part of their triennial review. During your assessment of the AU domain, you discovered that the contractor has recently installed new nodes and servers on their network infrastructure. To assess their implementation of AU.L2-3.3.7 – Authoritative Time Source, you trigger some events documented to meet AU.L2-3.3.1 – System Auditing across both the new and existing systems, generating audit logs. Upon examining these logs, you notice inconsistencies in the timestamps between newly installed and previously existing nodes. Further investigation reveals that while the contractor has implemented a central Network Time Protocol (NTP) server as the authoritative time source, the new systems are configured to automatically adjust and synchronize their clocks only when the time difference with the NTP server exceeds 30 seconds. Based on this scenario, why is time synchronization with the NTP server necessary, and what is the recommended synchronization time?