We are occasionally seeing this on some of our domain connected NAS boxes, but when I check the times they all appear accurate to the second:

Log Name: System
Source: Microsoft-Windows-Time-Service
Date: 14/12/2020 17:26:01
Event ID: 50
Task Category: None
Level: Warning
Keywords:
User: LOCAL SERVICE
Computer: GRNAS01.domain.local
Description:
The time service detected a time difference of greater than 5000 milliseconds for 900 seconds. The time difference might be caused by synchronization with low-accuracy time sources or by suboptimal network conditions. The time service is no longer synchronized and cannot provide the time to other clients or update the system clock. When a valid time stamp is received from a time service provider, the time service will correct itself.
Event Xml:



50
0
3
0
0
0x8000000000000000

9535


System
GRNAS01.domain.local



5000
900

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