Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753335AbZAETeh (ORCPT ); Mon, 5 Jan 2009 14:34:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751305AbZAETe2 (ORCPT ); Mon, 5 Jan 2009 14:34:28 -0500 Received: from hawking.rebel.net.au ([203.20.69.83]:43016 "EHLO hawking.rebel.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972AbZAETe1 (ORCPT ); Mon, 5 Jan 2009 14:34:27 -0500 Message-ID: <4961A9E2.9060601@davidnewall.com> Date: Mon, 05 Jan 2009 17:04:10 +1030 From: David Newall User-Agent: Thunderbird 2.0.0.12 (X11/20080227) MIME-Version: 1.0 To: Ben Goodger CC: david@lang.hm, Kyle Moffett , Robert Hancock , linux-kernel@vger.kernel.org, linasvepstas@gmail.com, "Jeffrey J. Kosowsky" , MentalMooMan , Travis Crump , burdell@iruntheinter.net Subject: Re: Bug: Status/Summary of slashdot leap-second crash on new years 2008-2009 References: <3ae3aa420901021125n1153053fsdf2378e7d11abbc0@mail.gmail.com> <496076A9.7030907@davidnewall.com> <4960897D.5030603@davidnewall.com> <4961432A.80509@davidnewall.com> <49614835.7000505@davidnewall.com> <496150DF.2070501@davidnewall.com> <8752a8760901041621o51380e91x9ef8414b22c40ffc@mail.gmail.com> In-Reply-To: <8752a8760901041621o51380e91x9ef8414b22c40ffc@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1231 Lines: 32 Ben Goodger wrote: > 2009/1/5 David Newall : > >>> another poster said that NTP packets include information about this >>> month's leap second, so that implies that they could change monthly. >>> >> Not "could change monthly" rather, "could change at any month". >> >> The frequency of zoneinfo updates would therefore be: every time the >> zones you care about change; and every time there's a leap second. No >> big effort. >> > > Unfortunately, as has been pointed out, timezones are completely > unrelated to leap seconds. > Zoneinfo files cater for leap seconds. > NB. Leap seconds, positive or negative, potentially occur every six > months (June 30 or Dec 31), but since their introduction this > frequency has happened only once (in 1972); historically they have > been inserted on average every 1.5 years, but there have been only two > since 2000. If you know in advance, you can update zoneinfo files with multiple leap seconds. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/