Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83 (MC830713); site vu44.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!panda!talcott!harvard!seismo!mcvax!vu44!tstorm From: tstorm@vu44.UUCP (Theo van der Storm) Newsgroups: net.bugs,net.flame,net.puzzle Subject: Re: Computer bugs in the year 2000 Message-ID: <587@vu44.UUCP> Date: Sun, 3-Feb-85 11:08:10 EST Article-I.D.: vu44.587 Posted: Sun Feb 3 11:08:10 1985 Date-Received: Tue, 5-Feb-85 03:56:01 EST References: <246@cheviot.UUCP> <974@utastro.UUCP> <7927@brl-tgr.ARPA> Reply-To: tstorm@vu44.UUCP (PUT YOUR NAME HERE) Distribution: net Organization: VU Informatica, Amsterdam Lines: 21 Keywords: leap year mean solar day Xref: watmath net.bugs:543 net.flame:8202 net.puzzle:544 Summary: WHY 2100, 2200, and 2300 leapyears and 2000, 2400 not. In article <7927@brl-tgr.ARPA> ron@brl-tgr.ARPA (Ron Natalie ) writes: >> For those of you fixing things in your software: >> >> The year 2000 *is* a leap year, despite what many algorithms tell you. >> The year 2400 is *not* a leap year. >> >> With minimal effort, you can make things work until 2399. You may be >> subject to complaints after that. >> >Now you've really got me confused. Why is 2400 not a leap year? (msd = mean solar day) 1 year = 365.2422 msd = 365 + 1/4 - 1/100 + 1/400 + error That's why we have: leapyear 1 out of 4 non leap year 1 out of 100 leapyear 1 out of 400 (So 2400 is a leap year.) Read any basic astronomy book. -- Theo van der Storm, 52 20'N / 4 52'E, {seismo|decvax|philabs}!mcvax!vu44!tstorm