Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers and Consumers (2009 edition)



Michael A. Lombardi, Andrew N. Novick, John P. Lowe, Matthew J. Deutch, Glenn K. Nelson, Douglas D. Sutton, William C. Yates, D. W. Hanson


Radio controlled clocks represent a true revolution in timekeeping. Clocks that synchronize to NIST radio station WWVB now number in the millions in the United States, and new sales records are being established every year. As a result, many of us are now accustomed to having clocks in our homes, offices, and on our wrists that always display the correct time and that never require adjustment. This NIST Recommended Practice Guide was written to provide guidance to both manufacturers and consumers of radio controlled clocks. Through voluntary compliance with the recommended practices listed here, manufacturers can benefit by continuing to develop more reliable and usable radio controlled products, increasing both consumer confidence and sales. Consumers can benefit by using this guide to help them select and purchase radio controlled clock products, to learn how the products work, and to help troubleshoot reception problems.
Special Publication (NIST SP) - 960-14-09
Report Number


radio controlled clocks, time, time-of-day, WWVB


Lombardi, M. , Novick, A. , Lowe, J. , Deutch, M. , Nelson, G. , Sutton, D. , Yates, W. and Hanson, D. (2009), WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers and Consumers (2009 edition), Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 30, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created September 8, 2009, Updated February 19, 2017