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