xref: /csrg-svn/share/zoneinfo/DIST/tzfile.h (revision 39989)

#ifndef lint
#ifndef NOID
#ifndef TZFILE_H
#define TZFILE_H
static char	tzfilehid[] = "@(#)tzfile.h	4.5";
#endif /* !defined TZFILE_H */
#endif /* !defined NOID */
#endif /* !defined lint */

/*
** Information about time zone files.
*/

#ifndef TZDIR
#define TZDIR		"/etc/zoneinfo"	/* Time zone object file directory */
#endif /* !defined TZDIR */

#ifndef TZDEFAULT
#define TZDEFAULT	"localtime"
#endif /* !defined TZDEFAULT */

#ifndef TZDEFRULES
#define TZDEFRULES	"posixrules"
#endif /* !defined TZDEFRULES */

/*
** Each file begins with. . .
*/

struct tzhead {
	char	tzh_reserved[24];	/* reserved for future use */
	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
	char	tzh_leapcnt[4];		/* coded number of leap seconds */
	char	tzh_timecnt[4];		/* coded number of transition times */
	char	tzh_typecnt[4];		/* coded number of local time types */
	char	tzh_charcnt[4];		/* coded number of abbr. chars */
};

/*
** . . .followed by. . .
**
**	tzh_timecnt (char [4])s		coded transition times a la time(2)
**	tzh_timecnt (unsigned char)s	types of local time starting at above
**	tzh_typecnt repetitions of
**		one (char [4])		coded GMT offset in seconds
**		one (unsigned char)	used to set tm_isdst
**		one (unsigned char)	that's an abbreviation list index
**	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
**	tzh_leapcnt repetitions of
**		one (char [4])		coded leap second transition times
**		one (char [4])		total correction after above
**	tzh_ttisstdcnt (char)s		indexed by type; if TRUE, transition
**					time is standard time, if FALSE,
**					transition time is wall clock time
**					if absent, transition times are
**					assumed to be wall clock time
*/

/*
** In the current implementation, "tzset()" refuses to deal with files that
** exceed any of the limits below.
*/

#ifndef TZ_MAX_TIMES
/*
** The TZ_MAX_TIMES value below is enough to handle a bit more than a
** year's worth of solar time (corrected daily to the nearest second) or
** 138 years of Pacific Presidential Election time
** (where there are three time zone transitions every fourth year).
*/
#define TZ_MAX_TIMES	370
#endif /* !defined TZ_MAX_TIMES */

#ifndef TZ_MAX_TYPES
#ifndef NOSOLAR
#define TZ_MAX_TYPES	256	/* Limited by what (unsigned char)'s can hold */
#else /* !defined NOSOLAR */
#define TZ_MAX_TYPES	10	/* Maximum number of local time types */
#endif /* !defined NOSOLAR */
#endif /* !defined TZ_MAX_TYPES */

#ifndef TZ_MAX_CHARS
#define TZ_MAX_CHARS	50	/* Maximum number of abbreviation characters */
#endif /* !defined TZ_MAX_CHARS */

#ifndef TZ_MAX_LEAPS
#define	TZ_MAX_LEAPS	50	/* Maximum number of leap second corrections */
#endif /* !defined TZ_MAX_LEAPS */

#define SECSPERMIN	60
#define MINSPERHOUR	60
#define HOURSPERDAY	24
#define DAYSPERWEEK	7
#define DAYSPERNYEAR	365
#define DAYSPERLYEAR	366
#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY	((long) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR	12

#define TM_SUNDAY	0
#define TM_MONDAY	1
#define TM_TUESDAY	2
#define TM_WEDNESDAY	3
#define TM_THURSDAY	4
#define TM_FRIDAY	5
#define TM_SATURDAY	6

#define TM_JANUARY	0
#define TM_FEBRUARY	1
#define TM_MARCH	2
#define TM_APRIL	3
#define TM_MAY		4
#define TM_JUNE		5
#define TM_JULY		6
#define TM_AUGUST	7
#define TM_SEPTEMBER	8
#define TM_OCTOBER	9
#define TM_NOVEMBER	10
#define TM_DECEMBER	11

#define TM_YEAR_BASE	1900

#define EPOCH_YEAR	1970
#define EPOCH_WDAY	TM_THURSDAY

/*
** Accurate only for the past couple of centuries;
** that will probably do.
*/

#define isleap(y) (((y) % 4) == 0 && ((y) % 100) != 0 || ((y) % 400) == 0)