1 /* 2 * ntp_calendar.h - definitions for the calendar time-of-day routine 3 */ 4 #ifndef NTP_CALENDAR_H 5 #define NTP_CALENDAR_H 6 7 #include <time.h> 8 9 #include "ntp_types.h" 10 11 /* gregorian calendar date */ 12 struct calendar { 13 uint16_t year; /* year (A.D.) */ 14 uint16_t yearday; /* day of year, 1 = January 1 */ 15 uint8_t month; /* month, 1 = January */ 16 uint8_t monthday; /* day of month */ 17 uint8_t hour; /* hour of day, midnight = 0 */ 18 uint8_t minute; /* minute of hour */ 19 uint8_t second; /* second of minute */ 20 uint8_t weekday; /* 0..7, 0=Sunday */ 21 }; 22 23 /* ISO week calendar date */ 24 struct isodate { 25 uint16_t year; /* year (A.D.) */ 26 uint8_t week; /* 1..53, week in year */ 27 uint8_t weekday; /* 1..7, 1=Monday */ 28 uint8_t hour; /* hour of day, midnight = 0 */ 29 uint8_t minute; /* minute of hour */ 30 uint8_t second; /* second of minute */ 31 }; 32 33 /* general split representation */ 34 typedef struct { 35 int32_t hi; 36 int32_t lo; 37 } ntpcal_split; 38 39 typedef time_t (*systime_func_ptr)(time_t *); 40 41 /* 42 * set the function for getting the system time. This is mostly used for 43 * unit testing to provide a fixed / shifted time stamp. Setting the 44 * value to NULL restores the original function, that is, 'time()', 45 * which is also the automatic default. 46 */ 47 extern systime_func_ptr ntpcal_set_timefunc(systime_func_ptr); 48 49 /* 50 * days-of-week 51 */ 52 #define CAL_SUNDAY 0 53 #define CAL_MONDAY 1 54 #define CAL_TUESDAY 2 55 #define CAL_WEDNESDAY 3 56 #define CAL_THURSDAY 4 57 #define CAL_FRIDAY 5 58 #define CAL_SATURDAY 6 59 #define CAL_SUNDAY7 7 /* also sunday */ 60 61 /* 62 * Days in each month. 30 days hath September... 63 */ 64 #define JAN 31 65 #define FEB 28 66 #define FEBLEAP 29 67 #define MAR 31 68 #define APR 30 69 #define MAY 31 70 #define JUN 30 71 #define JUL 31 72 #define AUG 31 73 #define SEP 30 74 #define OCT 31 75 #define NOV 30 76 #define DEC 31 77 78 /* 79 * We deal in a 4 year cycle starting at March 1, 1900. We assume 80 * we will only want to deal with dates since then, and not to exceed 81 * the rollover day in 2036. 82 */ 83 #define SECSPERMIN (60) /* seconds per minute */ 84 #define MINSPERHR (60) /* minutes per hour */ 85 #define HRSPERDAY (24) /* hours per day */ 86 #define DAYSPERWEEK (7) /* days per week */ 87 #define DAYSPERYEAR (365) /* days per year */ 88 89 #define SECSPERHR (SECSPERMIN * MINSPERHR) 90 #define SECSPERDAY (SECSPERHR * HRSPERDAY) 91 #define SECSPERWEEK (DAYSPERWEEK * SECSPERDAY) 92 #define SECSPERYEAR (365 * SECSPERDAY) /* regular year */ 93 #define SECSPERLEAPYEAR (366 * SECSPERDAY) /* leap year */ 94 #define SECSPERAVGYEAR 31556952 /* mean year length over 400yrs */ 95 96 /* 97 * Gross hacks. I have illicit knowlege that there won't be overflows 98 * here, the compiler often can't tell this. 99 */ 100 #define TIMES60(val) ((((val)<<4) - (val))<<2) /* *(16 - 1) * 4 */ 101 #define TIMES24(val) (((val)<<4) + ((val)<<3)) /* *16 + *8 */ 102 #define TIMES7(val) (((val)<<3) - (val)) /* *8 - *1 */ 103 #define TIMESDPERC(val) (((val)<<10) + ((val)<<8) \ 104 + ((val)<<7) + ((val)<<5) \ 105 + ((val)<<4) + ((val)<<2) + (val)) /* *big* hack */ 106 107 108 extern const char * const months[12]; 109 extern const char * const daynames[7]; 110 111 extern void caljulian (uint32_t, struct calendar *); 112 extern uint32_t caltontp (const struct calendar *); 113 114 /* 115 * Convert between 'time_t' and 'vint64' 116 */ 117 extern vint64 time_to_vint64(const time_t *); 118 extern time_t vint64_to_time(const vint64 *); 119 120 /* 121 * Get the build date & time. ATTENTION: The time zone is not specified! 122 * This depends entirely on the C compilers' capabilities to properly 123 * expand the '__TIME__' and '__DATE__' macros, as required by the C 124 * standard. 125 */ 126 extern int 127 ntpcal_get_build_date(struct calendar * /* jd */); 128 129 /* 130 * Convert a timestamp in NTP scale to a time_t value in the UN*X 131 * scale with proper epoch unfolding around a given pivot or the 132 * current system time. 133 */ 134 extern vint64 135 ntpcal_ntp_to_time(uint32_t /* ntp */, const time_t * /* pivot */); 136 137 /* 138 * Convert a timestamp in NTP scale to a 64bit seconds value in the NTP 139 * scale with proper epoch unfolding around a given pivot or the current 140 * system time. 141 * Note: The pivot must be given in UN*X time scale! 142 */ 143 extern vint64 144 ntpcal_ntp_to_ntp(uint32_t /* ntp */, const time_t * /* pivot */); 145 146 /* 147 * Split a time stamp in seconds into elapsed days and elapsed seconds 148 * since midnight. 149 */ 150 extern ntpcal_split 151 ntpcal_daysplit(const vint64 *); 152 153 /* 154 * Merge a number of days and a number of seconds into seconds, 155 * expressed in 64 bits to avoid overflow. 156 */ 157 extern vint64 158 ntpcal_dayjoin(int32_t /* days */, int32_t /* seconds */); 159 160 /* Get the number of leap years since epoch for the number of elapsed 161 * full years 162 */ 163 extern int32_t 164 ntpcal_leapyears_in_years(int32_t /* years */); 165 166 /* 167 * Convert elapsed years in Era into elapsed days in Era. 168 */ 169 extern int32_t 170 ntpcal_days_in_years(int32_t /* years */); 171 172 /* 173 * Convert a number of elapsed month in a year into elapsed days 174 * in year. 175 * 176 * The month will be normalized, and 'res.hi' will contain the 177 * excessive years that must be considered when converting the years, 178 * while 'res.lo' will contain the days since start of the 179 * year. (Expect the resulting days to be negative, with a positive 180 * excess! But then, we need no leap year flag, either...) 181 */ 182 extern ntpcal_split 183 ntpcal_days_in_months(int32_t /* months */); 184 185 /* 186 * Convert ELAPSED years/months/days of gregorian calendar to elapsed 187 * days in Gregorian epoch. No range checks done here! 188 */ 189 extern int32_t 190 ntpcal_edate_to_eradays(int32_t /* years */, int32_t /* months */, int32_t /* mdays */); 191 192 /* 193 * Convert a time spec to seconds. No range checks done here! 194 */ 195 extern int32_t 196 ntpcal_etime_to_seconds(int32_t /* hours */, int32_t /* minutes */, int32_t /* seconds */); 197 198 /* 199 * Convert ELAPSED years/months/days of gregorian calendar to elapsed 200 * days in year. 201 * 202 * Note: This will give the true difference to the start of the given year, 203 * even if months & days are off-scale. 204 */ 205 extern int32_t 206 ntpcal_edate_to_yeardays(int32_t /* years */, int32_t /* months */, int32_t /* mdays */); 207 208 /* 209 * Convert the date part of a 'struct tm' (that is, year, month, 210 * day-of-month) into the RataDie of that day. 211 */ 212 extern int32_t 213 ntpcal_tm_to_rd(const struct tm * /* utm */); 214 215 /* 216 * Convert the date part of a 'struct calendar' (that is, year, month, 217 * day-of-month) into the RataDie of that day. 218 */ 219 extern int32_t 220 ntpcal_date_to_rd(const struct calendar * /* jt */); 221 222 /* 223 * Given the number of elapsed days in the calendar era, split this 224 * number into the number of elapsed years in 'res.quot' and the 225 * number of elapsed days of that year in 'res.rem'. 226 * 227 * if 'isleapyear' is not NULL, it will receive an integer that is 0 228 * for regular years and a non-zero value for leap years. 229 * 230 * The input is limited to [-2^30, 2^30-1]. If the days exceed this 231 * range, errno is set to EDOM and the result is saturated. 232 */ 233 extern ntpcal_split 234 ntpcal_split_eradays(int32_t /* days */, int/*BOOL*/ * /* isleapyear */); 235 236 /* 237 * Given a number of elapsed days in a year and a leap year indicator, 238 * split the number of elapsed days into the number of elapsed months 239 * in 'res.quot' and the number of elapsed days of that month in 240 * 'res.rem'. 241 */ 242 extern ntpcal_split 243 ntpcal_split_yeardays(int32_t /* eyd */, int/*BOOL*/ /* isleapyear */); 244 245 /* 246 * Convert a RataDie number into the date part of a 'struct 247 * calendar'. Return 0 if the year is regular year, !0 if the year is 248 * a leap year. 249 */ 250 extern int/*BOOL*/ 251 ntpcal_rd_to_date(struct calendar * /* jt */, int32_t /* rd */); 252 253 /* 254 * Convert a RataDie number into the date part of a 'struct 255 * tm'. Return 0 if the year is regular year, !0 if the year is a leap 256 * year. 257 */ 258 extern int/*BOOL*/ 259 ntpcal_rd_to_tm(struct tm * /* utm */, int32_t /* rd */); 260 261 /* 262 * Take a value of seconds since midnight and split it into hhmmss in 263 * a 'struct calendar'. Return excessive days. 264 */ 265 extern int32_t 266 ntpcal_daysec_to_date(struct calendar * /* jt */, int32_t /* secs */); 267 268 /* 269 * Take the time part of a 'struct calendar' and return the seconds 270 * since midnight. 271 */ 272 extern int32_t 273 ntpcal_date_to_daysec(const struct calendar *); 274 275 /* 276 * Take a value of seconds since midnight and split it into hhmmss in 277 * a 'struct tm'. Return excessive days. 278 */ 279 extern int32_t 280 ntpcal_daysec_to_tm(struct tm * /* utm */, int32_t /* secs */); 281 282 extern int32_t 283 ntpcal_tm_to_daysec(const struct tm * /* utm */); 284 285 /* 286 * convert a year number to rata die of year start 287 */ 288 extern int32_t 289 ntpcal_year_to_ystart(int32_t /* year */); 290 291 /* 292 * For a given RataDie, get the RataDie of the associated year start, 293 * that is, the RataDie of the last January,1st on or before that day. 294 */ 295 extern int32_t 296 ntpcal_rd_to_ystart(int32_t /* rd */); 297 298 /* 299 * convert a RataDie to the RataDie of start of the calendar month. 300 */ 301 extern int32_t 302 ntpcal_rd_to_mstart(int32_t /* year */); 303 304 305 extern int 306 ntpcal_daysplit_to_date(struct calendar * /* jt */, 307 const ntpcal_split * /* ds */, int32_t /* dof */); 308 309 extern int 310 ntpcal_daysplit_to_tm(struct tm * /* utm */, const ntpcal_split * /* ds */, 311 int32_t /* dof */); 312 313 extern int 314 ntpcal_time_to_date(struct calendar * /* jd */, const vint64 * /* ts */); 315 316 extern int32_t 317 ntpcal_periodic_extend(int32_t /* pivot */, int32_t /* value */, 318 int32_t /* cycle */); 319 320 extern int 321 ntpcal_ntp64_to_date(struct calendar * /* jd */, const vint64 * /* ntp */); 322 323 extern int 324 ntpcal_ntp_to_date(struct calendar * /* jd */, uint32_t /* ntp */, 325 const time_t * /* pivot */); 326 327 extern vint64 328 ntpcal_date_to_ntp64(const struct calendar * /* jd */); 329 330 extern uint32_t 331 ntpcal_date_to_ntp(const struct calendar * /* jd */); 332 333 extern time_t 334 ntpcal_date_to_time(const struct calendar * /* jd */); 335 336 /* 337 * ISO week-calendar conversions 338 */ 339 extern int32_t 340 isocal_weeks_in_years(int32_t /* years */); 341 342 /* 343 * The input is limited to [-2^30, 2^30-1]. If the weeks exceed this 344 * range, errno is set to EDOM and the result is saturated. 345 */ 346 extern ntpcal_split 347 isocal_split_eraweeks(int32_t /* weeks */); 348 349 extern int 350 isocal_ntp64_to_date(struct isodate * /* id */, const vint64 * /* ntp */); 351 352 extern int 353 isocal_ntp_to_date(struct isodate * /* id */, uint32_t /* ntp */, 354 const time_t * /* pivot */); 355 356 extern vint64 357 isocal_date_to_ntp64(const struct isodate * /* id */); 358 359 extern uint32_t 360 isocal_date_to_ntp(const struct isodate * /* id */); 361 362 363 /* 364 * day-of-week calculations 365 * 366 * Given a RataDie and a day-of-week, calculate a RDN that is reater-than, 367 * greater-or equal, closest, less-or-equal or less-than the given RDN 368 * and denotes the given day-of-week 369 */ 370 extern int32_t 371 ntpcal_weekday_gt(int32_t /* rdn */, int32_t /* dow */); 372 373 extern int32_t 374 ntpcal_weekday_ge(int32_t /* rdn */, int32_t /* dow */); 375 376 extern int32_t 377 ntpcal_weekday_close(int32_t /* rdn */, int32_t /* dow */); 378 379 extern int32_t 380 ntpcal_weekday_le(int32_t /* rdn */, int32_t /* dow */); 381 382 extern int32_t 383 ntpcal_weekday_lt(int32_t /* rdn */, int32_t /* dow */); 384 385 386 /* 387 * handling of base date spec 388 */ 389 extern int32_t 390 basedate_eval_buildstamp(void); 391 392 extern int32_t 393 basedate_eval_string(const char *str); 394 395 extern int32_t 396 basedate_set_day(int32_t dayno); 397 398 extern uint32_t 399 basedate_get_day(void); 400 401 extern time_t 402 basedate_get_eracenter(void); 403 404 extern time_t 405 basedate_get_erabase(void); 406 407 408 /* 409 * Additional support stuff for Ed Rheingold's calendrical calculations 410 */ 411 412 /* 413 * Start day of NTP time as days past the imaginary date 12/1/1 BC. 414 * (This is the beginning of the Christian Era, or BCE.) 415 */ 416 #define DAY_NTP_STARTS 693596 417 418 /* 419 * Start day of the UNIX epoch. This is the Rata Die of 1970-01-01. 420 */ 421 #define DAY_UNIX_STARTS 719163 422 423 /* 424 * Difference between UN*X and NTP epoch (25567). 425 */ 426 #define NTP_TO_UNIX_DAYS (DAY_UNIX_STARTS - DAY_NTP_STARTS) 427 428 /* 429 * Days in a normal 4 year leap year calendar cycle (1461). 430 */ 431 #define GREGORIAN_NORMAL_LEAP_CYCLE_DAYS (3 * 365 + 366) 432 433 /* 434 * Days in a normal 100 year leap year calendar (36524). We lose a 435 * leap day in years evenly divisible by 100 but not by 400. 436 */ 437 #define GREGORIAN_NORMAL_CENTURY_DAYS \ 438 (25 * GREGORIAN_NORMAL_LEAP_CYCLE_DAYS - 1) 439 440 /* 441 * The Gregorian calendar is based on a 400 year cycle. This is the 442 * number of days in each cycle (146097). We gain a leap day in years 443 * divisible by 400 relative to the "normal" century. 444 */ 445 #define GREGORIAN_CYCLE_DAYS (4 * GREGORIAN_NORMAL_CENTURY_DAYS + 1) 446 447 /* 448 * Number of weeks in 400 years (20871). 449 */ 450 #define GREGORIAN_CYCLE_WEEKS (GREGORIAN_CYCLE_DAYS / 7) 451 452 #define is_leapyear(y) (!((y) % 4) && !(!((y) % 100) && (y) % 400)) 453 454 #endif 455