One of my first problems when I took my current Sys Admin and Netowrk Admin position, the CEO was crazed because the clinets workstations did not update the correct time from the Domain Controller. Nothing was sync.
So becasue I am ex-military and worked 15 years for DOD, I decided to sync the DC to the U.S. NAVY Time server, have been using it for 3 years now and it has never failed.
I wanted to give you the registry entry incase you a plagued with this issue as well. Perform on DC:
1. REGEDIT
2. HKLM \SYSTEM \CurrentControlSet\SERVICES \W32TIME \PARAMETERS \TYPE
(NT5DS)
3. HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags (change this
value from 10 to 5
4. HKLM\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer (change this from
time.windows.com,0X1 to tock.usno.navy.mil,0X1
5. SAVE - EXIT
6. Uses Port 123
Hope this helps