Time and Frequency Services

The Time and Frequency Services group distributes standard time and frequency signals generated by the Coordinated Universal Time scale, UTC(NIST), that is maintained at the NIST laboratories in Boulder, Colorado.  UTC(NIST) is the U. S. national standard for measurements of time-of-day, time interval, and frequency.

UTC(NIST) is freely distributed to many millions of users through radio, Internet, and telephone links.  The services that distribute UTC(NIST) include shortwave radio stations WWV and WWVH, low frequency radio station WWVB, the Internet Time Service (ITS), the Automated Computer Time Service (ACTS), the telephone time service, and the web clock (time.gov).  These services synchronize hundreds of millions of clock every day.

UTC(NIST) is also distributed through remote calibration services to paying customers who need the highest levels of accuracy.  The demanding measurement needs of these customers are met through the Frequency Measurement and Analysis Service (FMAS) and the Time Measurement and Analysis Service (TMAS).