Learn about the features of this software for keeping precise time by referencing atomic readings. Download a demo and decide whether to buy.

Shop for watches and alarm, desk, wall, and digital clocks which update themselves automatically by referring to official US government time.

Explains the technology and physical principles involved in these clocks and discusses the different kinds in operation.

Download software which will automatically update a computer's clock based on official atomic-clock readings.

Describes the different kinds of atomic clocks and explains how they operate. Provides links to related articles.

Helps maintain standards for time and frequency in the United States. Offers official time, radio station databases, FAQ, glossary and services.