Usually the synchronization process (using NTP protocol) is executed each 2 hours but when using Kerberos method, the synchronization is not performed and Artica server can loose time between the Active Directory.
This behaviour is correct when using NTLM method.
see: Time Synchronization with Active Directory
This issue can be resolved using a special fix that you can download here:
It can be applied only for all versions before 4.30x Service Pack 323 using the same method to apply a Service Pack