Time Protocol
RFC 868, “Time Protocol”, is an Internet Standard document published in May 1983 by J. Postel, K. Harrenstien. The canonical text is published by the RFC Editor.
Abstract
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.
What “Internet Standard” means
A mature, widely-implemented specification that has completed the full IETF standards process — the highest maturity level on the standards track.
The canonical text of RFC 868 is hosted at rfc-editor.org. Available in TXT,HTML.