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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).



Frequency Measurement and Analysis Service (FMAS)—The NIST Frequency Measurement and Analysis Service (FMAS) makes it easy to measure and calibrate any quartz, rubidium, cesium, or hydrogen maser frequency standard. The service can measure any …

Time Measurement and Analysis Service (TMAS)—The NIST Time Measurement and Analysis Service (TMAS) was designed to assist laboratories that maintain an accurate local time standard. The service monitors the customer's local time standard by …


John Lowe, Group Leader

General Information:
303-497-3295 Telephone
303-497-6461 Facsimile

325 Broadway, M/S 847.4
Boulder, CO 80305