xref: /original-bsd/include/tzfile.h (revision c3e32dec)
1 /*
2  * Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Arthur David Olson of the National Cancer Institute.
7  *
8  * %sccs.include.redist.c%
9  *
10  *	@(#)tzfile.h	8.1 (Berkeley) 06/02/93
11  */
12 
13 #ifndef _TZFILE_H_
14 #define	_TZFILE_H_
15 
16 /*
17  * Information about time zone files.
18  */
19 			/* Time zone object file directory */
20 #define TZDIR		"/usr/share/zoneinfo"
21 #define TZDEFAULT	"/etc/localtime"
22 #define TZDEFRULES	"posixrules"
23 
24 /*
25 ** Each file begins with. . .
26 */
27 
28 struct tzhead {
29 	char	tzh_reserved[24];	/* reserved for future use */
30 	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
31 	char	tzh_leapcnt[4];		/* coded number of leap seconds */
32 	char	tzh_timecnt[4];		/* coded number of transition times */
33 	char	tzh_typecnt[4];		/* coded number of local time types */
34 	char	tzh_charcnt[4];		/* coded number of abbr. chars */
35 };
36 
37 /*
38 ** . . .followed by. . .
39 **
40 **	tzh_timecnt (char [4])s		coded transition times a la time(2)
41 **	tzh_timecnt (unsigned char)s	types of local time starting at above
42 **	tzh_typecnt repetitions of
43 **		one (char [4])		coded GMT offset in seconds
44 **		one (unsigned char)	used to set tm_isdst
45 **		one (unsigned char)	that's an abbreviation list index
46 **	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
47 **	tzh_leapcnt repetitions of
48 **		one (char [4])		coded leap second transition times
49 **		one (char [4])		total correction after above
50 **	tzh_ttisstdcnt (char)s		indexed by type; if TRUE, transition
51 **					time is standard time, if FALSE,
52 **					transition time is wall clock time
53 **					if absent, transition times are
54 **					assumed to be wall clock time
55 */
56 
57 /*
58 ** In the current implementation, "tzset()" refuses to deal with files that
59 ** exceed any of the limits below.
60 */
61 
62 /*
63 ** The TZ_MAX_TIMES value below is enough to handle a bit more than a
64 ** year's worth of solar time (corrected daily to the nearest second) or
65 ** 138 years of Pacific Presidential Election time
66 ** (where there are three time zone transitions every fourth year).
67 */
68 #define TZ_MAX_TIMES	370
69 
70 #define NOSOLAR			/* 4BSD doesn't currently handle solar time */
71 
72 #ifndef NOSOLAR
73 #define TZ_MAX_TYPES	256	/* Limited by what (unsigned char)'s can hold */
74 #else
75 #define TZ_MAX_TYPES	10	/* Maximum number of local time types */
76 #endif
77 
78 #define TZ_MAX_CHARS	50	/* Maximum number of abbreviation characters */
79 
80 #define	TZ_MAX_LEAPS	50	/* Maximum number of leap second corrections */
81 
82 #define SECSPERMIN	60
83 #define MINSPERHOUR	60
84 #define HOURSPERDAY	24
85 #define DAYSPERWEEK	7
86 #define DAYSPERNYEAR	365
87 #define DAYSPERLYEAR	366
88 #define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
89 #define SECSPERDAY	((long) SECSPERHOUR * HOURSPERDAY)
90 #define MONSPERYEAR	12
91 
92 #define TM_SUNDAY	0
93 #define TM_MONDAY	1
94 #define TM_TUESDAY	2
95 #define TM_WEDNESDAY	3
96 #define TM_THURSDAY	4
97 #define TM_FRIDAY	5
98 #define TM_SATURDAY	6
99 
100 #define TM_JANUARY	0
101 #define TM_FEBRUARY	1
102 #define TM_MARCH	2
103 #define TM_APRIL	3
104 #define TM_MAY		4
105 #define TM_JUNE		5
106 #define TM_JULY		6
107 #define TM_AUGUST	7
108 #define TM_SEPTEMBER	8
109 #define TM_OCTOBER	9
110 #define TM_NOVEMBER	10
111 #define TM_DECEMBER	11
112 
113 #define TM_YEAR_BASE	1900
114 
115 #define EPOCH_YEAR	1970
116 #define EPOCH_WDAY	TM_THURSDAY
117 
118 /*
119 ** Accurate only for the past couple of centuries;
120 ** that will probably do.
121 */
122 
123 #define isleap(y) (((y) % 4) == 0 && ((y) % 100) != 0 || ((y) % 400) == 0)
124 
125 #endif /* !_TZFILE_H_ */
126