1*4887Schin /*********************************************************************** 2*4887Schin * * 3*4887Schin * This software is part of the ast package * 4*4887Schin * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5*4887Schin * and is licensed under the * 6*4887Schin * Common Public License, Version 1.0 * 7*4887Schin * by AT&T Knowledge Ventures * 8*4887Schin * * 9*4887Schin * A copy of the License is available at * 10*4887Schin * http://www.opensource.org/licenses/cpl1.0.txt * 11*4887Schin * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12*4887Schin * * 13*4887Schin * Information and Software Systems Research * 14*4887Schin * AT&T Research * 15*4887Schin * Florham Park NJ * 16*4887Schin * * 17*4887Schin * Glenn Fowler <gsf@research.att.com> * 18*4887Schin * David Korn <dgk@research.att.com> * 19*4887Schin * Phong Vo <kpv@research.att.com> * 20*4887Schin * * 21*4887Schin ***********************************************************************/ 22*4887Schin #pragma prototyped 23*4887Schin /* 24*4887Schin * Glenn Fowler 25*4887Schin * AT&T Research 26*4887Schin * 27*4887Schin * time_t conversion support 28*4887Schin */ 29*4887Schin 30*4887Schin #include <tm.h> 31*4887Schin 32*4887Schin /* 33*4887Schin * use one of the 14 equivalent calendar years to determine 34*4887Schin * daylight savings time for future years beyond the range 35*4887Schin * of the local system (via tmxmake()) 36*4887Schin */ 37*4887Schin 38*4887Schin static const short equiv[] = 39*4887Schin { 40*4887Schin 2006, 2012, 41*4887Schin 2001, 2024, 42*4887Schin 2002, 2008, 43*4887Schin 2003, 2020, 44*4887Schin 2009, 2004, 45*4887Schin 2010, 2016, 46*4887Schin 2005, 2000, 47*4887Schin }; 48*4887Schin 49*4887Schin /* 50*4887Schin * return the circa 2000 equivalent calendar year for tm 51*4887Schin */ 52*4887Schin 53*4887Schin int 54*4887Schin tmequiv(Tm_t* tm) 55*4887Schin { 56*4887Schin return tm->tm_year < (2038 - 1900) ? (tm->tm_year + 1900) : equiv[tm->tm_wday + tmisleapyear(tm->tm_year)]; 57*4887Schin } 58