Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!lll-winken!uunet!mcsun!ukc!strath-cs!expya!exua!JRowe From: JRowe@exua.exeter.ac.uk (John Rowe) Newsgroups: comp.unix.questions Subject: Re: Why does "cal 9 1752" produce incorrect results? Message-ID: Date: 29 Nov 90 18:25:04 GMT References: <3313@ns-mx.uiowa.edu> Sender: JRowe@exua.exeter.ac.uk Organization: Computer Unit. - University of Exeter. UK Lines: 27 In-reply-to: khenry@umaxc.weeg.uiowa.edu's message of 27 Nov 90 01:29:16 GMT It doesn't. (Sorry if you've already had dozens of versions of the following posted). Under the old Julien calender, instituted by Julius Caeser no less, there was a leap year every four years. I believe it was the Egyptians who discovered this one because the seasons and the flooding of the Nile were happening later every year. It turned out this was slightly too many so the system was changed so that years divisable by 100 are not leap years unless they are divisable by 400 (eg 1900 wasn't, 2000 will be). My dictionary says this was done by Pope Gregory in 1582 but not adopted in England 'till - you guessed it 1752 when people went to bed on Wednesday the 2nd of September and got up on Thursday the 14th. Incidently, as I recall there were great protests about this as people thought they were losing 11 days of their lives. Plus, the Russians being backward didn't do this which is why the October revolution didn't happen in October, rather like the battle of Stalingrad which happened in Volgagrad. John John Rowe Exeter University Computational Physics group. Exeter England.