tzfile.h revision 1.9
1 /* $NetBSD: tzfile.h,v 1.9 2019/04/04 18:18:52 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 /* See Internet RFC 8536 for more details about the following format. */ 37 38 /* 39 ** Each file begins with. . . 40 */ 41 42 #define TZ_MAGIC "TZif" 43 44 struct tzhead { 45 char tzh_magic[4]; /* TZ_MAGIC */ 46 char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */ 47 char tzh_reserved[15]; /* reserved; must be zero */ 48 char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */ 49 char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */ 50 char tzh_leapcnt[4]; /* coded number of leap seconds */ 51 char tzh_timecnt[4]; /* coded number of transition times */ 52 char tzh_typecnt[4]; /* coded number of local time types */ 53 char tzh_charcnt[4]; /* coded number of abbr. chars */ 54 }; 55 56 /* 57 ** . . .followed by. . . 58 ** 59 ** tzh_timecnt (char [4])s coded transition times a la time(2) 60 ** tzh_timecnt (unsigned char)s types of local time starting at above 61 ** tzh_typecnt repetitions of 62 ** one (char [4]) coded UT offset in seconds 63 ** one (unsigned char) used to set tm_isdst 64 ** one (unsigned char) that's an abbreviation list index 65 ** tzh_charcnt (char)s '\0'-terminated zone abbreviations 66 ** tzh_leapcnt repetitions of 67 ** one (char [4]) coded leap second transition times 68 ** one (char [4]) total correction after above 69 ** tzh_ttisstdcnt (char)s indexed by type; if 1, transition 70 ** time is standard time, if 0, 71 ** transition time is wall clock time 72 ** if absent, transition times are 73 ** assumed to be wall clock time 74 ** tzh_ttisgmtcnt (char)s indexed by type; if 1, transition 75 ** time is UT, if 0, 76 ** transition time is local time 77 ** if absent, transition times are 78 ** assumed to be local time 79 */ 80 81 /* 82 ** If tzh_version is '2' or greater, the above is followed by a second instance 83 ** of tzhead and a second instance of the data in which each coded transition 84 ** time uses 8 rather than 4 chars, 85 ** then a POSIX-TZ-environment-variable-style string for use in handling 86 ** instants after the last transition time stored in the file 87 ** (with nothing between the newlines if there is no POSIX representation for 88 ** such instants). 89 ** 90 ** If tz_version is '3' or greater, the above is extended as follows. 91 ** First, the POSIX TZ string's hour offset may range from -167 92 ** through 167 as compared to the POSIX-required 0 through 24. 93 ** Second, its DST start time may be January 1 at 00:00 and its stop 94 ** time December 31 at 24:00 plus the difference between DST and 95 ** standard time, indicating DST all year. 96 */ 97 98 /* 99 ** In the current implementation, "tzset()" refuses to deal with files that 100 ** exceed any of the limits below. 101 */ 102 103 #ifndef TZ_MAX_TIMES 104 #define TZ_MAX_TIMES 2000 105 #endif /* !defined TZ_MAX_TIMES */ 106 107 #ifndef TZ_MAX_TYPES 108 /* This must be at least 17 for Europe/Samara and Europe/Vilnius. */ 109 #define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */ 110 #endif /* !defined TZ_MAX_TYPES */ 111 112 #ifndef TZ_MAX_CHARS 113 #define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */ 114 /* (limited by what unsigned chars can hold) */ 115 #endif /* !defined TZ_MAX_CHARS */ 116 117 #ifndef TZ_MAX_LEAPS 118 #define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */ 119 #endif /* !defined TZ_MAX_LEAPS */ 120 121 #define SECSPERMIN 60 122 #define MINSPERHOUR 60 123 #define HOURSPERDAY 24 124 #define DAYSPERWEEK 7 125 #define DAYSPERNYEAR 365 126 #define DAYSPERLYEAR 366 127 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) 128 #define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY) 129 #define MONSPERYEAR 12 130 131 #define TM_SUNDAY 0 132 #define TM_MONDAY 1 133 #define TM_TUESDAY 2 134 #define TM_WEDNESDAY 3 135 #define TM_THURSDAY 4 136 #define TM_FRIDAY 5 137 #define TM_SATURDAY 6 138 139 #define TM_JANUARY 0 140 #define TM_FEBRUARY 1 141 #define TM_MARCH 2 142 #define TM_APRIL 3 143 #define TM_MAY 4 144 #define TM_JUNE 5 145 #define TM_JULY 6 146 #define TM_AUGUST 7 147 #define TM_SEPTEMBER 8 148 #define TM_OCTOBER 9 149 #define TM_NOVEMBER 10 150 #define TM_DECEMBER 11 151 152 #define TM_YEAR_BASE 1900 153 154 #define EPOCH_YEAR 1970 155 #define EPOCH_WDAY TM_THURSDAY 156 157 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0)) 158 159 /* 160 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that 161 ** isleap(y) == isleap(y % 400) 162 ** and so 163 ** isleap(a + b) == isleap((a + b) % 400) 164 ** or 165 ** isleap(a + b) == isleap(a % 400 + b % 400) 166 ** This is true even if % means modulo rather than Fortran remainder 167 ** (which is allowed by C89 but not C99). 168 ** We use this to avoid addition overflow problems. 169 */ 170 171 #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400) 172 173 #endif /* !defined _TZFILE_H_ */ 174
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