|Network Working Group
Request for Comments: 868
J. Postel — ISI
K. Harrenstien — SRI
This RFC specifies a standard for the ARPA Internet community. Hosts on the ARPA Internet that choose to implement a Time Protocol are expected to adopt and implement this standard.
This protocol provides a site-independent, machine readable date and time. The Time service sends back to the originating source the time in seconds since midnight on January first 1900.
One motivation arises from the fact that not all systems have a date/time clock, and all are subject to occasional human or machine error. The use of time-servers makes it possible to quickly confirm or correct a system’s idea of the time, by making a brief poll of several
This protocol may be used either above the Transmission Control Protocol (TCP) or above the User Datagram Protocol (UDP).
When used via TCP the time service works as follows:
When used via UDP the time service works as follows:
The time is the number of seconds since 00:00 (midnight) 1 January 1900 GMT, such that the time 1 is 12:00:01 am on 1 January 1900 GMT; this base will serve until the year 2036.