The NIST Digital Time Service

Abstract : The NIST Digital Time Service is designed to provide computers with telephone access to time generated by the National Institute of Standards and Technology (NIST, formerly the National Bureau of Standards) at accuracies approaching 1 ms. Features of the service include automated estimation by the transmitter of the telephone-line delay, advanced alert for changes to and from daylight saving time and advanced notice of insertion of leap seconds. The ASCH-character time code operates with most clocks and simple hardware can also be developed to set non-computer clock systems.