tmequiv.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2007 AT&T Knowledge Ventures *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Knowledge Ventures *
* *
* A copy of the License is available at *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Research
*
* time_t conversion support
*/
#include <tm.h>
/*
* use one of the 14 equivalent calendar years to determine
* daylight savings time for future years beyond the range
* of the local system (via tmxmake())
*/
static const short equiv[] =
{
2006, 2012,
2001, 2024,
2002, 2008,
2003, 2020,
2009, 2004,
2010, 2016,
2005, 2000,
};
/*
* return the circa 2000 equivalent calendar year for tm
*/
int
{
return tm->tm_year < (2038 - 1900) ? (tm->tm_year + 1900) : equiv[tm->tm_wday + tmisleapyear(tm->tm_year)];
}