tzfile.h 5.0 KB

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  1. #ifndef TZFILE_H
  2. #define TZFILE_H
  3. /*
  4. ** This file is in the public domain, so clarified as of
  5. ** 1996-06-05 by Arthur David Olson.
  6. */
  7. /*
  8. ** This header is for use ONLY with the time conversion code.
  9. ** There is no guarantee that it will remain unchanged,
  10. ** or that it will remain at all.
  11. ** Do NOT copy it to any system include directory.
  12. ** Thank you!
  13. */
  14. /*
  15. ** Information about time zone files.
  16. */
  17. #ifndef TZDIR
  18. #define TZDIR "/usr/local/etc/zoneinfo" /* Time zone object file directory */
  19. #endif /* !defined TZDIR */
  20. #ifndef TZDEFAULT
  21. #define TZDEFAULT "localtime"
  22. #endif /* !defined TZDEFAULT */
  23. #ifndef TZDEFRULES
  24. #define TZDEFRULES "posixrules"
  25. #endif /* !defined TZDEFRULES */
  26. /*
  27. ** Each file begins with. . .
  28. */
  29. #define TZ_MAGIC "TZif"
  30. struct tzhead {
  31. char tzh_magic[4]; /* TZ_MAGIC */
  32. char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */
  33. char tzh_reserved[15]; /* reserved--must be zero */
  34. char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */
  35. char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */
  36. char tzh_leapcnt[4]; /* coded number of leap seconds */
  37. char tzh_timecnt[4]; /* coded number of transition times */
  38. char tzh_typecnt[4]; /* coded number of local time types */
  39. char tzh_charcnt[4]; /* coded number of abbr. chars */
  40. };
  41. /*
  42. ** . . .followed by. . .
  43. **
  44. ** tzh_timecnt (char [4])s coded transition times a la time(2)
  45. ** tzh_timecnt (unsigned char)s types of local time starting at above
  46. ** tzh_typecnt repetitions of
  47. ** one (char [4]) coded UT offset in seconds
  48. ** one (unsigned char) used to set tm_isdst
  49. ** one (unsigned char) that's an abbreviation list index
  50. ** tzh_charcnt (char)s '\0'-terminated zone abbreviations
  51. ** tzh_leapcnt repetitions of
  52. ** one (char [4]) coded leap second transition times
  53. ** one (char [4]) total correction after above
  54. ** tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition
  55. ** time is standard time, if FALSE,
  56. ** transition time is wall clock time
  57. ** if absent, transition times are
  58. ** assumed to be wall clock time
  59. ** tzh_ttisgmtcnt (char)s indexed by type; if TRUE, transition
  60. ** time is UT, if FALSE,
  61. ** transition time is local time
  62. ** if absent, transition times are
  63. ** assumed to be local time
  64. */
  65. /*
  66. ** If tzh_version is '2' or greater, the above is followed by a second instance
  67. ** of tzhead and a second instance of the data in which each coded transition
  68. ** time uses 8 rather than 4 chars,
  69. ** then a POSIX-TZ-environment-variable-style string for use in handling
  70. ** instants after the last transition time stored in the file
  71. ** (with nothing between the newlines if there is no POSIX representation for
  72. ** such instants).
  73. **
  74. ** If tz_version is '3' or greater, the above is extended as follows.
  75. ** First, the POSIX TZ string's hour offset may range from -167
  76. ** through 167 as compared to the POSIX-required 0 through 24.
  77. ** Second, its DST start time may be January 1 at 00:00 and its stop
  78. ** time December 31 at 24:00 plus the difference between DST and
  79. ** standard time, indicating DST all year.
  80. */
  81. /*
  82. ** In the current implementation, "tzset()" refuses to deal with files that
  83. ** exceed any of the limits below.
  84. */
  85. #ifndef TZ_MAX_TIMES
  86. #define TZ_MAX_TIMES 2000
  87. #endif /* !defined TZ_MAX_TIMES */
  88. #ifndef TZ_MAX_TYPES
  89. /* This must be at least 17 for Europe/Samara and Europe/Vilnius. */
  90. #define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
  91. #endif /* !defined TZ_MAX_TYPES */
  92. #ifndef TZ_MAX_CHARS
  93. #define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */
  94. /* (limited by what unsigned chars can hold) */
  95. #endif /* !defined TZ_MAX_CHARS */
  96. #ifndef TZ_MAX_LEAPS
  97. #define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */
  98. #endif /* !defined TZ_MAX_LEAPS */
  99. #define SECSPERMIN 60
  100. #define MINSPERHOUR 60
  101. #define HOURSPERDAY 24
  102. #define DAYSPERWEEK 7
  103. #define DAYSPERNYEAR 365
  104. #define DAYSPERLYEAR 366
  105. #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
  106. #define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
  107. #define MONSPERYEAR 12
  108. #define TM_SUNDAY 0
  109. #define TM_MONDAY 1
  110. #define TM_TUESDAY 2
  111. #define TM_WEDNESDAY 3
  112. #define TM_THURSDAY 4
  113. #define TM_FRIDAY 5
  114. #define TM_SATURDAY 6
  115. #define TM_JANUARY 0
  116. #define TM_FEBRUARY 1
  117. #define TM_MARCH 2
  118. #define TM_APRIL 3
  119. #define TM_MAY 4
  120. #define TM_JUNE 5
  121. #define TM_JULY 6
  122. #define TM_AUGUST 7
  123. #define TM_SEPTEMBER 8
  124. #define TM_OCTOBER 9
  125. #define TM_NOVEMBER 10
  126. #define TM_DECEMBER 11
  127. #define TM_YEAR_BASE 1900
  128. #define EPOCH_YEAR 1970
  129. #define EPOCH_WDAY TM_THURSDAY
  130. #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
  131. /*
  132. ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
  133. ** isleap(y) == isleap(y % 400)
  134. ** and so
  135. ** isleap(a + b) == isleap((a + b) % 400)
  136. ** or
  137. ** isleap(a + b) == isleap(a % 400 + b % 400)
  138. ** This is true even if % means modulo rather than Fortran remainder
  139. ** (which is allowed by C89 but not C99).
  140. ** We use this to avoid addition overflow problems.
  141. */
  142. #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
  143. #endif /* !defined TZFILE_H */