minix3-3.4.0/include/tzfile.h

1 /*	$NetBSD: tzfile.h,v 1.8 2015/07/11 16:40:53 christos Exp $	*/
2 
3 #ifndef _TZFILE_H_
4 #define _TZFILE_H_
5 
6 /*
7 ** This file is in the public domain, so clarified as of
8 ** 1996-06-05 by Arthur David Olson.
9 */
10 
11 /*
12 ** This header is for use ONLY with the time conversion code.
13 ** There is no guarantee that it will remain unchanged,
14 ** or that it will remain at all.
15 ** Do NOT copy it to any system include directory.
16 ** Thank you!
17 */
18 
19 /*
20 ** Information about time zone files.
21 */
22 
23 #ifndef TZDIR		/* Time zone object file directory */
24 #define TZDIR		"/usr/share/zoneinfo"
25 #endif /* !defined TZDIR */
26 
27 #ifndef TZDEFAULT
28 #define TZDEFAULT	"/etc/localtime"
29 #endif /* !defined TZDEFAULT */
30 
31 #ifndef TZDEFRULES
32 #define TZDEFRULES	"posixrules"
33 #endif /* !defined TZDEFRULES */
34 
35 /*
36 ** Each file begins with. . .
37 */
38 
39 #define	TZ_MAGIC	"TZif"
40 
41 struct tzhead {
42 	char	tzh_magic[4];		/* TZ_MAGIC */
43 	char	tzh_version[1];		/* '\0' or '2' or '3' as of 2013 */
44 	char	tzh_reserved[15];	/* reserved; must be zero */
45 	char	tzh_ttisgmtcnt[4];	/* coded number of trans. time flags */
46 	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
47 	char	tzh_leapcnt[4];		/* coded number of leap seconds */
48 	char	tzh_timecnt[4];		/* coded number of transition times */
49 	char	tzh_typecnt[4];		/* coded number of local time types */
50 	char	tzh_charcnt[4];		/* coded number of abbr. chars */
51 };
52 
53 /*
54 ** . . .followed by. . .
55 **
56 **	tzh_timecnt (char [4])s		coded transition times a la time(2)
57 **	tzh_timecnt (unsigned char)s	types of local time starting at above
58 **	tzh_typecnt repetitions of
59 **		one (char [4])		coded UT offset in seconds
60 **		one (unsigned char)	used to set tm_isdst
61 **		one (unsigned char)	that's an abbreviation list index
62 **	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
63 **	tzh_leapcnt repetitions of
64 **		one (char [4])		coded leap second transition times
65 **		one (char [4])		total correction after above
66 **	tzh_ttisstdcnt (char)s		indexed by type; if 1, transition
67 **					time is standard time, if 0,
68 **					transition time is wall clock time
69 **					if absent, transition times are
70 **					assumed to be wall clock time
71 **	tzh_ttisgmtcnt (char)s		indexed by type; if 1, transition
72 **					time is UT, if 0,
73 **					transition time is local time
74 **					if absent, transition times are
75 **					assumed to be local time
76 */
77 
78 /*
79 ** If tzh_version is '2' or greater, the above is followed by a second instance
80 ** of tzhead and a second instance of the data in which each coded transition
81 ** time uses 8 rather than 4 chars,
82 ** then a POSIX-TZ-environment-variable-style string for use in handling
83 ** instants after the last transition time stored in the file
84 ** (with nothing between the newlines if there is no POSIX representation for
85 ** such instants).
86 **
87 ** If tz_version is '3' or greater, the above is extended as follows.
88 ** First, the POSIX TZ string's hour offset may range from -167
89 ** through 167 as compared to the POSIX-required 0 through 24.
90 ** Second, its DST start time may be January 1 at 00:00 and its stop
91 ** time December 31 at 24:00 plus the difference between DST and
92 ** standard time, indicating DST all year.
93 */
94 
95 /*
96 ** In the current implementation, "tzset()" refuses to deal with files that
97 ** exceed any of the limits below.
98 */
99 
100 #ifndef TZ_MAX_TIMES
101 #define TZ_MAX_TIMES	2000
102 #endif /* !defined TZ_MAX_TIMES */
103 
104 #ifndef TZ_MAX_TYPES
105 /* This must be at least 17 for Europe/Samara and Europe/Vilnius.  */
106 #define TZ_MAX_TYPES	256 /* Limited by what (unsigned char)'s can hold */
107 #endif /* !defined TZ_MAX_TYPES */
108 
109 #ifndef TZ_MAX_CHARS
110 #define TZ_MAX_CHARS	50	/* Maximum number of abbreviation characters */
111 				/* (limited by what unsigned chars can hold) */
112 #endif /* !defined TZ_MAX_CHARS */
113 
114 #ifndef TZ_MAX_LEAPS
115 #define TZ_MAX_LEAPS	50	/* Maximum number of leap second corrections */
116 #endif /* !defined TZ_MAX_LEAPS */
117 
118 #define SECSPERMIN	60
119 #define MINSPERHOUR	60
120 #define HOURSPERDAY	24
121 #define DAYSPERWEEK	7
122 #define DAYSPERNYEAR	365
123 #define DAYSPERLYEAR	366
124 #define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
125 #define SECSPERDAY	((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
126 #define MONSPERYEAR	12
127 
128 #define TM_SUNDAY	0
129 #define TM_MONDAY	1
130 #define TM_TUESDAY	2
131 #define TM_WEDNESDAY	3
132 #define TM_THURSDAY	4
133 #define TM_FRIDAY	5
134 #define TM_SATURDAY	6
135 
136 #define TM_JANUARY	0
137 #define TM_FEBRUARY	1
138 #define TM_MARCH	2
139 #define TM_APRIL	3
140 #define TM_MAY		4
141 #define TM_JUNE		5
142 #define TM_JULY		6
143 #define TM_AUGUST	7
144 #define TM_SEPTEMBER	8
145 #define TM_OCTOBER	9
146 #define TM_NOVEMBER	10
147 #define TM_DECEMBER	11
148 
149 #define TM_YEAR_BASE	1900
150 
151 #define EPOCH_YEAR	1970
152 #define EPOCH_WDAY	TM_THURSDAY
153 
154 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
155 
156 /*
157 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
158 **	isleap(y) == isleap(y % 400)
159 ** and so
160 **	isleap(a + b) == isleap((a + b) % 400)
161 ** or
162 **	isleap(a + b) == isleap(a % 400 + b % 400)
163 ** This is true even if % means modulo rather than Fortran remainder
164 ** (which is allowed by C89 but not C99).
165 ** We use this to avoid addition overflow problems.
166 */
167 
168 #define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
169 
170 #endif /* !defined _TZFILE_H_ */