tzfile.h revision 1.8
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_ */ 171
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