We recently had an issue with our time source and it caused us a bit a of a head ache. It turns out that our time source was a router that lost its time and therefore affected the our DCs. I issued the following command on on the DC holding the PDC Emulator Role and it immediately solved our issue. .
w32tm /config /manualpeerlist:time.windows.com /syncfromflags:manual /reliable:yes /update
the m anualpeerlist is where multiple sources are specified but I only included the time.windows.com source and it worked.
Configure The Time Source for the Forest
