6 ** This file is in the public domain, so clarified as of
7 ** 1996-06-05 by Arthur David Olson.
13 ** This header is for use ONLY with the time conversion code.
14 ** There is no guarantee that it will remain unchanged,
15 ** or that it will remain at all.
16 ** Do NOT copy it to any system include directory.
27 static char tzfilehid[] = "@(#)tzfile.h 8.1";
29 #endif /* !defined NOID */
30 #endif /* !defined lint */
33 ** Information about time zone files.
37 #define TZDIR "/usr/share/zoneinfo" /* Time zone object file directory */
38 #endif /* !defined TZDIR */
41 #define TZDEFAULT "/etc/localtime"
42 #endif /* !defined TZDEFAULT */
45 #define TZDEFRULES "posixrules"
46 #endif /* !defined TZDEFRULES */
49 ** Each file begins with. . .
52 #define TZ_MAGIC "TZif"
55 char tzh_magic[4]; /* TZ_MAGIC */
56 char tzh_version[1]; /* '\0' or '2' as of 2005 */
57 char tzh_reserved[15]; /* reserved--must be zero */
58 char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */
59 char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */
60 char tzh_leapcnt[4]; /* coded number of leap seconds */
61 char tzh_timecnt[4]; /* coded number of transition times */
62 char tzh_typecnt[4]; /* coded number of local time types */
63 char tzh_charcnt[4]; /* coded number of abbr. chars */
67 ** . . .followed by. . .
69 ** tzh_timecnt (char [4])s coded transition times a la time(2)
70 ** tzh_timecnt (unsigned char)s types of local time starting at above
71 ** tzh_typecnt repetitions of
72 ** one (char [4]) coded UTC offset in seconds
73 ** one (unsigned char) used to set tm_isdst
74 ** one (unsigned char) that's an abbreviation list index
75 ** tzh_charcnt (char)s '\0'-terminated zone abbreviations
76 ** tzh_leapcnt repetitions of
77 ** one (char [4]) coded leap second transition times
78 ** one (char [4]) total correction after above
79 ** tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition
80 ** time is standard time, if FALSE,
81 ** transition time is wall clock time
82 ** if absent, transition times are
83 ** assumed to be wall clock time
84 ** tzh_ttisgmtcnt (char)s indexed by type; if TRUE, transition
85 ** time is UTC, if FALSE,
86 ** transition time is local time
87 ** if absent, transition times are
88 ** assumed to be local time
92 ** If tzh_version is '2' or greater, the above is followed by a second instance
93 ** of tzhead and a second instance of the data in which each coded transition
94 ** time uses 8 rather than 4 chars,
95 ** then a POSIX-TZ-environment-variable-style string for use in handling
96 ** instants after the last transition time stored in the file
97 ** (with nothing between the newlines if there is no POSIX representation for
102 ** In the current implementation, "tzset()" refuses to deal with files that
103 ** exceed any of the limits below.
107 #define TZ_MAX_TIMES 1200
108 #endif /* !defined TZ_MAX_TIMES */
112 #define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
113 #endif /* !defined NOSOLAR */
116 ** Must be at least 14 for Europe/Riga as of Jan 12 1995,
117 ** as noted by Earl Chew.
119 #define TZ_MAX_TYPES 20 /* Maximum number of local time types */
120 #endif /* !defined NOSOLAR */
121 #endif /* !defined TZ_MAX_TYPES */
124 #define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */
125 /* (limited by what unsigned chars can hold) */
126 #endif /* !defined TZ_MAX_CHARS */
129 #define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */
130 #endif /* !defined TZ_MAX_LEAPS */
132 #define SECSPERMIN 60
133 #define MINSPERHOUR 60
134 #define HOURSPERDAY 24
135 #define DAYSPERWEEK 7
136 #define DAYSPERNYEAR 365
137 #define DAYSPERLYEAR 366
138 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
139 #define SECSPERDAY ((long) SECSPERHOUR * HOURSPERDAY)
140 #define MONSPERYEAR 12
145 #define TM_WEDNESDAY 3
146 #define TM_THURSDAY 4
148 #define TM_SATURDAY 6
151 #define TM_FEBRUARY 1
158 #define TM_SEPTEMBER 8
160 #define TM_NOVEMBER 10
161 #define TM_DECEMBER 11
163 #define TM_YEAR_BASE 1900
165 #define EPOCH_YEAR 1970
166 #define EPOCH_WDAY TM_THURSDAY
168 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
171 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
172 ** isleap(y) == isleap(y % 400)
174 ** isleap(a + b) == isleap((a + b) % 400)
176 ** isleap(a + b) == isleap(a % 400 + b % 400)
177 ** This is true even if % means modulo rather than Fortran remainder
178 ** (which is allowed by C89 but not C99).
179 ** We use this to avoid addition overflow problems.
182 #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
184 #endif /* !defined TZFILE_H */