From owner-freebsd-questions Mon Oct 27 16:15:04 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id QAA08411 for questions-outgoing; Mon, 27 Oct 1997 16:15:04 -0800 (PST) (envelope-from owner-freebsd-questions) Received: from rvc1.informatik.ba-stuttgart.de (rvc1.informatik.ba-stuttgart.de [141.31.112.22]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id QAA08384 for ; Mon, 27 Oct 1997 16:14:51 -0800 (PST) (envelope-from helbig@Informatik.BA-Stuttgart.DE) Received: (from helbig@localhost) by rvc1.informatik.ba-stuttgart.de (8.8.7/8.8.5) id AAA21304; Tue, 28 Oct 1997 00:40:41 +0100 (MET) From: Wolfgang Helbig Message-Id: <199710272340.AAA21304@rvc1.informatik.ba-stuttgart.de> Subject: Re: 2000 Compliance / dates / time libs In-Reply-To: from jack at "Oct 27, 97 01:09:34 pm" To: jack@diamond.xtalwind.net (jack) Date: Tue, 28 Oct 1997 00:39:25 +0100 (MET) Cc: steve@visint.co.uk, freebsd-questions@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL30 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > On Tue, 29 Feb 2000, Stephen Roome wrote: > > > > > So when (or if) does the julian/gregorian switch take place > > It already happened, in the 1500s. The exact year varied by country. The switch took place October 4th 1582, which was followed by the October 15th 1582. At least that's what the catholic church determined. The switch was necassary, because the calendar and the revolution of the earth around the sun (or the sun around the earth :-) got out of synch. Especially April 21st was not the start of spring anymore which confused the calculation of easter. The old Julian calendar defines a leap year as every year divisible by four. The new Gregorian calendar defines a leap year as every year divisible by four and not divisible by hundred or divisible by 400. Hence for the year 2000 it does not matter: Since it's divisible by four it's a leap year according to Julius Caesar and since it's divisible by 400 it's a leap year according to Pope Gregor. BTW. The usr/src/share/zoneinfo files contain the switch date for some countries. Wolfgang