| /* Layout and location of TZif files. */ | |
| #ifndef TZFILE_H | |
| #define TZFILE_H | |
| /* | |
| ** This file is in the public domain, so clarified as of | |
| ** 1996-06-05 by Arthur David Olson. | |
| */ | |
| /* | |
| ** This header is for use ONLY with the time conversion code. | |
| ** There is no guarantee that it will remain unchanged, | |
| ** or that it will remain at all. | |
| ** Do NOT copy it to any system include directory. | |
| ** Thank you! | |
| */ | |
| /* | |
| ** Information about time zone files. | |
| */ | |
| #ifndef TZDIR | |
| # define TZDIR "/usr/share/zoneinfo" /* Time zone object file directory */ | |
| #endif /* !defined TZDIR */ | |
| #ifndef TZDEFAULT | |
| # define TZDEFAULT "/etc/localtime" | |
| #endif /* !defined TZDEFAULT */ | |
| #ifndef TZDEFRULES | |
| # define TZDEFRULES "posixrules" | |
| #endif /* !defined TZDEFRULES */ | |
| /* See Internet RFC 8536 for more details about the following format. */ | |
| /* | |
| ** Each file begins with. . . | |
| */ | |
| #define TZ_MAGIC "TZif" | |
| struct tzhead { | |
| char tzh_magic[4]; /* TZ_MAGIC */ | |
| char tzh_version[1]; /* '\0' or '2'-'4' as of 2021 */ | |
| char tzh_reserved[15]; /* reserved; must be zero */ | |
| char tzh_ttisutcnt[4]; /* coded number of trans. time flags */ | |
| char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */ | |
| char tzh_leapcnt[4]; /* coded number of leap seconds */ | |
| char tzh_timecnt[4]; /* coded number of transition times */ | |
| char tzh_typecnt[4]; /* coded number of local time types */ | |
| char tzh_charcnt[4]; /* coded number of abbr. chars */ | |
| }; | |
| /* | |
| ** . . .followed by. . . | |
| ** | |
| ** tzh_timecnt (char [4])s coded transition times a la time(2) | |
| ** tzh_timecnt (unsigned char)s types of local time starting at above | |
| ** tzh_typecnt repetitions of | |
| ** one (char [4]) coded UT offset in seconds | |
| ** one (unsigned char) used to set tm_isdst | |
| ** one (unsigned char) that's an abbreviation list index | |
| ** tzh_charcnt (char)s '\0'-terminated zone abbreviations | |
| ** tzh_leapcnt repetitions of | |
| ** one (char [4]) coded leap second transition times | |
| ** one (char [4]) total correction after above | |
| ** tzh_ttisstdcnt (char)s indexed by type; if 1, transition | |
| ** time is standard time, if 0, | |
| ** transition time is local (wall clock) | |
| ** time; if absent, transition times are | |
| ** assumed to be local time | |
| ** tzh_ttisutcnt (char)s indexed by type; if 1, transition | |
| ** time is UT, if 0, transition time is | |
| ** local time; if absent, transition | |
| ** times are assumed to be local time. | |
| ** When this is 1, the corresponding | |
| ** std/wall indicator must also be 1. | |
| */ | |
| /* | |
| ** If tzh_version is '2' or greater, the above is followed by a second instance | |
| ** of tzhead and a second instance of the data in which each coded transition | |
| ** time uses 8 rather than 4 chars, | |
| ** then a POSIX-TZ-environment-variable-style string for use in handling | |
| ** instants after the last transition time stored in the file | |
| ** (with nothing between the newlines if there is no POSIX representation for | |
| ** such instants). | |
| ** | |
| ** If tz_version is '3' or greater, the above is extended as follows. | |
| ** First, the POSIX TZ string's hour offset may range from -167 | |
| ** through 167 as compared to the POSIX-required 0 through 24. | |
| ** Second, its DST start time may be January 1 at 00:00 and its stop | |
| ** time December 31 at 24:00 plus the difference between DST and | |
| ** standard time, indicating DST all year. | |
| */ | |
| /* | |
| ** In the current implementation, "tzset()" refuses to deal with files that | |
| ** exceed any of the limits below. | |
| */ | |
| #ifndef TZ_MAX_TIMES | |
| /* This must be at least 242 for Europe/London with 'zic -b fat'. */ | |
| # define TZ_MAX_TIMES 2000 | |
| #endif /* !defined TZ_MAX_TIMES */ | |
| #ifndef TZ_MAX_TYPES | |
| /* This must be at least 18 for Europe/Vilnius with 'zic -b fat'. */ | |
| # define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */ | |
| #endif /* !defined TZ_MAX_TYPES */ | |
| #ifndef TZ_MAX_CHARS | |
| /* This must be at least 40 for America/Anchorage. */ | |
| # define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */ | |
| /* (limited by what unsigned chars can hold) */ | |
| #endif /* !defined TZ_MAX_CHARS */ | |
| #ifndef TZ_MAX_LEAPS | |
| /* This must be at least 27 for leap seconds from 1972 through mid-2023. | |
| There's a plan to discontinue leap seconds by 2035. */ | |
| # define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */ | |
| #endif /* !defined TZ_MAX_LEAPS */ | |
| #define SECSPERMIN 60 | |
| #define MINSPERHOUR 60 | |
| #define HOURSPERDAY 24 | |
| #define DAYSPERWEEK 7 | |
| #define DAYSPERNYEAR 365 | |
| #define DAYSPERLYEAR 366 | |
| #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) | |
| #define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY) | |
| #define MONSPERYEAR 12 | |
| #define TM_SUNDAY 0 | |
| #define TM_MONDAY 1 | |
| #define TM_TUESDAY 2 | |
| #define TM_WEDNESDAY 3 | |
| #define TM_THURSDAY 4 | |
| #define TM_FRIDAY 5 | |
| #define TM_SATURDAY 6 | |
| #define TM_JANUARY 0 | |
| #define TM_FEBRUARY 1 | |
| #define TM_MARCH 2 | |
| #define TM_APRIL 3 | |
| #define TM_MAY 4 | |
| #define TM_JUNE 5 | |
| #define TM_JULY 6 | |
| #define TM_AUGUST 7 | |
| #define TM_SEPTEMBER 8 | |
| #define TM_OCTOBER 9 | |
| #define TM_NOVEMBER 10 | |
| #define TM_DECEMBER 11 | |
| #define TM_YEAR_BASE 1900 | |
| #define EPOCH_YEAR 1970 | |
| #define EPOCH_WDAY TM_THURSDAY | |
| #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0)) | |
| /* | |
| ** Since everything in isleap is modulo 400 (or a factor of 400), we know that | |
| ** isleap(y) == isleap(y % 400) | |
| ** and so | |
| ** isleap(a + b) == isleap((a + b) % 400) | |
| ** or | |
| ** isleap(a + b) == isleap(a % 400 + b % 400) | |
| ** This is true even if % means modulo rather than Fortran remainder | |
| ** (which is allowed by C89 but not C99). | |
| ** We use this to avoid addition overflow problems. | |
| */ | |
| #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400) | |
| #endif /* !defined TZFILE_H */ |