The NIST Internet Time Service (ITS) provides the official United States time, synchronized directly to the NIST atomic clock ensemble.
The generic address time.nist.gov is the recommended entry point: it resolves to available NIST servers and is suitable for everyday clients as well as legally traceable time needs within the US.
| Hostname | Note |
|---|---|
time.nist.gov
| Anycast / automatic selection |
time.nist.gov automatically selects among NIST's stratum-1 time servers; individual named hosts (time-a.nist.gov etc.) exist for specific servers.