Windows Time!

Came across a problem today. Has anyone or does anyone know how to solve it? 5 geographic sites, some with differnt time zones. The main site picks up time from the internet and all other sites (are supposed to sync). I couldn’t even sync the main site with the Internet. Everytime I changed it, went right back to 12 1/2 hr plus a day different..that changed also). Finally I got them all changed ..manually.
I checked viruses,,and virus server..
This has happened 3 days in a row now. There is no other admin (all cut off)
go figure