tmequiv.c revision 1
1N/A/***********************************************************************
1N/A* *
1N/A* This software is part of the ast package *
1N/A* Copyright (c) 1985-2011 AT&T Intellectual Property *
1N/A* and is licensed under the *
1N/A* Common Public License, Version 1.0 *
1N/A* by AT&T Intellectual Property *
1N/A* *
1N/A* A copy of the License is available at *
1N/A* http://www.opensource.org/licenses/cpl1.0.txt *
1N/A* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
1N/A* *
1N/A* Information and Software Systems Research *
1N/A* AT&T Research *
1N/A* Florham Park NJ *
1N/A* *
1N/A* Glenn Fowler <gsf@research.att.com> *
1N/A* David Korn <dgk@research.att.com> *
1N/A* Phong Vo <kpv@research.att.com> *
1N/A* *
1N/A***********************************************************************/
1N/A#pragma prototyped
1N/A/*
1N/A * Glenn Fowler
1N/A * AT&T Research
1N/A *
1N/A * time_t conversion support
1N/A */
1N/A
1N/A#include <tm.h>
1N/A
1N/A/*
1N/A * use one of the 14 equivalent calendar years to determine
1N/A * daylight savings time for future years beyond the range
1N/A * of the local system (via tmxtm())
1N/A */
1N/A
1N/Astatic const short equiv[] =
1N/A{
1N/A 2006, 2012,
1N/A 2001, 2024,
1N/A 2002, 2008,
1N/A 2003, 2020,
1N/A 2009, 2004,
1N/A 2010, 2016,
1N/A 2005, 2000,
1N/A};
1N/A
1N/A/*
1N/A * return the circa 2000 equivalent calendar year for tm
1N/A */
1N/A
1N/Aint
1N/Atmequiv(Tm_t* tm)
1N/A{
1N/A return tm->tm_year < (2038 - 1900) ? (tm->tm_year + 1900) : equiv[tm->tm_wday + tmisleapyear(tm->tm_year)];
1N/A}