All servers on the domain will get their time from a Domain Controller, specifically the domain that holds the PDC Emulator FSMO role. Without the correct time on the PDC Emulator amongst other things authentication could fail as time sync would be out between the Kerberos authentication protocol on client and DC.
If you do find any servers or a DC out of sync then the first thing to do would be to find the main PDC Emulator for the Domain or you could check the following registry key to see if the DC your on is getting its time from another DC or the internet:
Then Look at the Type Key
If it’s set as NTP then its going out to the internet to get its time and the website it’s going to will be set above under the key NtpServer.
If it’s set as NT5DS – The time service synchronizes from the domain hierarchy (so the PDC Emulator).
Once you’ve found the correct DC, you’ll need to force it to resync with the Internet:
Log on as an Administrator
Open up Command prompt in Admin mode
Type: w32tm /resync /rediscover
Then check the time.
Then go to the other DC’s and check the time, if its not caught up with the new time then run the following: