Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site hou3c.UUCP Path: utzoo!linus!decvax!genrad!grkermit!masscomp!clyde!burl!hou3c!RSX-DEV@DEC-MARLBORO.ARPA From: RSX-DEV@DEC-MARLBORO.ARPA Newsgroups: net.mail.headers Subject: GMT vs UCT Message-ID: <197@hou3c.UUCP> Date: Sat, 4-Feb-84 01:38:00 EST Article-I.D.: hou3c.197 Posted: Sat Feb 4 01:38:00 1984 Date-Received: Sun, 5-Feb-84 04:15:25 EST Sender: ka@hou3c.UUCP (Kenneth Almquist) Lines: 17 Enet-Address: "Castor::Covert" Phone: "(603) 884-8271 or DTN 264-8271" Usenet-Address: "{ucbvax,allegra,decvax}!decwrl!rhea!castor!covert" Greenwich Mean Time is solar time at the the Greenwich Meridian; it varies with the variations in the rotation of the the earth. Coordinated Universal Time is an absolute time which can differ from GMT by almost a second. Leap seconds are inserted when convenient to keep UTC within one second of GMT. UTC is easier to track at independent locations on earth because all you need is the proper oscillator (I think the element used recently changed). To track GMT, you need an observatory. I've never heard GCT used related to time (I always thought it was Grand Central Terminal :-) --------