timezone/tzfile.h

   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 ** ID
  20 */
  21
  22 #ifndef lint
  23 #ifndef NOID
  24 static char     tzfilehid[] = "@(#)tzfile.h     8.1";
  25 #endif /* !defined NOID */
  26 #endif /* !defined lint */
  27
  28 /*
  29 ** Information about time zone files.
  30 */
  31
  32 #ifndef TZDIR
  33 #define TZDIR   "/usr/local/etc/zoneinfo" /* Time zone object file directory */
  34 #endif /* !defined TZDIR */
  35
  36 #ifndef TZDEFAULT
  37 #define TZDEFAULT       "localtime"
  38 #endif /* !defined TZDEFAULT */
  39
  40 #ifndef TZDEFRULES
  41 #define TZDEFRULES      "posixrules"
  42 #endif /* !defined TZDEFRULES */
  43
  44 /*
  45 ** Each file begins with. . .
  46 */
  47
  48 #define TZ_MAGIC        "TZif"
  49
  50 struct tzhead {
  51         char    tzh_magic[4];           /* TZ_MAGIC */
  52         char    tzh_version[1];         /* '\0' or '2' as of 2005 */
  53         char    tzh_reserved[15];       /* reserved--must be zero */
  54         char    tzh_ttisgmtcnt[4];      /* coded number of trans. time flags */
  55         char    tzh_ttisstdcnt[4];      /* coded number of trans. time flags */
  56         char    tzh_leapcnt[4];         /* coded number of leap seconds */
  57         char    tzh_timecnt[4];         /* coded number of transition times */
  58         char    tzh_typecnt[4];         /* coded number of local time types */
  59         char    tzh_charcnt[4];         /* coded number of abbr. chars */
  60 };
  61
  62 /*
  63 ** . . .followed by. . .
  64 **
  65 **      tzh_timecnt (char [4])s         coded transition times a la time(2)
  66 **      tzh_timecnt (unsigned char)s    types of local time starting at above
  67 **      tzh_typecnt repetitions of
  68 **              one (char [4])          coded UTC offset in seconds
  69 **              one (unsigned char)     used to set tm_isdst
  70 **              one (unsigned char)     that's an abbreviation list index
  71 **      tzh_charcnt (char)s             '\0'-terminated zone abbreviations
  72 **      tzh_leapcnt repetitions of
  73 **              one (char [4])          coded leap second transition times
  74 **              one (char [4])          total correction after above
  75 **      tzh_ttisstdcnt (char)s          indexed by type; if TRUE, transition
  76 **                                      time is standard time, if FALSE,
  77 **                                      transition time is wall clock time
  78 **                                      if absent, transition times are
  79 **                                      assumed to be wall clock time
  80 **      tzh_ttisgmtcnt (char)s          indexed by type; if TRUE, transition
  81 **                                      time is UTC, if FALSE,
  82 **                                      transition time is local time
  83 **                                      if absent, transition times are
  84 **                                      assumed to be local time
  85 */
  86
  87 /*
  88 ** If tzh_version is '2' or greater, the above is followed by a second instance
  89 ** of tzhead and a second instance of the data in which each coded transition
  90 ** time uses 8 rather than 4 chars,
  91 ** then a POSIX-TZ-environment-variable-style string for use in handling
  92 ** instants after the last transition time stored in the file
  93 ** (with nothing between the newlines if there is no POSIX representation for
  94 ** such instants).
  95 */
  96
  97 /*
  98 ** In the current implementation, "tzset()" refuses to deal with files that
  99 ** exceed any of the limits below.
 100 */
 101
 102 #ifndef TZ_MAX_TIMES
 103 #define TZ_MAX_TIMES    1200
 104 #endif /* !defined TZ_MAX_TIMES */
 105
 106 #ifndef TZ_MAX_TYPES
 107 #ifndef NOSOLAR
 108 #define TZ_MAX_TYPES    256 /* Limited by what (unsigned char)'s can hold */
 109 #endif /* !defined NOSOLAR */
 110 #ifdef NOSOLAR
 111 /*
 112 ** Must be at least 14 for Europe/Riga as of Jan 12 1995,
 113 ** as noted by Earl Chew.
 114 */
 115 #define TZ_MAX_TYPES    20      /* Maximum number of local time types */
 116 #endif /* !defined NOSOLAR */
 117 #endif /* !defined TZ_MAX_TYPES */
 118
 119 #ifndef TZ_MAX_CHARS
 120 #define TZ_MAX_CHARS    50      /* Maximum number of abbreviation characters */
 121                                 /* (limited by what unsigned chars can hold) */
 122 #endif /* !defined TZ_MAX_CHARS */
 123
 124 #ifndef TZ_MAX_LEAPS
 125 #define TZ_MAX_LEAPS    50      /* Maximum number of leap second corrections */
 126 #endif /* !defined TZ_MAX_LEAPS */
 127
 128 #define SECSPERMIN      60
 129 #define MINSPERHOUR     60
 130 #define HOURSPERDAY     24
 131 #define DAYSPERWEEK     7
 132 #define DAYSPERNYEAR    365
 133 #define DAYSPERLYEAR    366
 134 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
 135 #define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
 136 #define MONSPERYEAR     12
 137
 138 #define TM_SUNDAY       0
 139 #define TM_MONDAY       1
 140 #define TM_TUESDAY      2
 141 #define TM_WEDNESDAY    3
 142 #define TM_THURSDAY     4
 143 #define TM_FRIDAY       5
 144 #define TM_SATURDAY     6
 145
 146 #define TM_JANUARY      0
 147 #define TM_FEBRUARY     1
 148 #define TM_MARCH        2
 149 #define TM_APRIL        3
 150 #define TM_MAY          4
 151 #define TM_JUNE         5
 152 #define TM_JULY         6
 153 #define TM_AUGUST       7
 154 #define TM_SEPTEMBER    8
 155 #define TM_OCTOBER      9
 156 #define TM_NOVEMBER     10
 157 #define TM_DECEMBER     11
 158
 159 #define TM_YEAR_BASE    1900
 160
 161 #define EPOCH_YEAR      1970
 162 #define EPOCH_WDAY      TM_THURSDAY
 163
 164 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
 165
 166 /*
 167 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
 168 **      isleap(y) == isleap(y % 400)
 169 ** and so
 170 **      isleap(a + b) == isleap((a + b) % 400)
 171 ** or
 172 **      isleap(a + b) == isleap(a % 400 + b % 400)
 173 ** This is true even if % means modulo rather than Fortran remainder
 174 ** (which is allowed by C89 but not C99).
 175 ** We use this to avoid addition overflow problems.
 176 */
 177
 178 #define isleap_sum(a, b)        isleap((a) % 400 + (b) % 400)
 179
 180 #endif /* !defined TZFILE_H */