The Windows Time service (also known as W32time) synchronizes the date and time for computers running on a Windows Server ...

The Windows Time service (also known as W32time) synchronizes the date and time for computers running on a Windows Server 2008 network. The Windows Time service is essential to the successful operation of Kerberos authentication and, therefore, to Active Directory–based authentication. Any Kerberos-aware application, including most security services, relies on time synchronization between the computers that are participating in the authentication request. Active Directory domain controllers must also have synchronized clocks to help ensure accurate data replication.