U.S.N.O. Master Clock Facility, Washington, DC

"Time is a great teacher, but unfortunately it kills all its pupils." -- Hector Berlioz

Precise Time & the USNO Master Clock

The US Naval Observatory Time Scale

International Time Scales and the BIPM

Definitions of Systems of Time at USNO

NAVSTAR GPS Timing Operations

Send comments on this page and those below it to Dr. Demetrios Matsakis, Director, Time Service Dept. Matsakis.Demetrios@usno.navy.mil

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