/* * ntp_calendar.h - definitions for the calendar time-of-day routine */ #ifndef NTP_CALENDAR_H #define NTP_CALENDAR_H #include <time.h> #include "ntp_types.h" /* gregorian calendar date */ struct calendar { uint16_t year; /* year (A.D.) */ uint16_t yearday; /* day of year, 1 = January 1 */ uint8_t month; /* month, 1 = January */ uint8_t monthday; /* day of month */ uint8_t hour; /* hour of day, midnight = 0 */ uint8_t minute; /* minute of hour */ uint8_t second; /* second of minute */ uint8_t weekday; /* 0..7, 0=Sunday */ }; /* ISO week calendar date */ struct isodate { uint16_t year; /* year (A.D.) */ uint8_t week; /* 1..53, week in year */ uint8_t weekday; /* 1..7, 1=Monday */ uint8_t hour; /* hour of day, midnight = 0 */ uint8_t minute; /* minute of hour */ uint8_t second; /* second of minute */ }; /* general split representation */ typedef struct { int32_t hi; int32_t lo; } ntpcal_split; typedef time_t (*systime_func_ptr)(time_t *); /* * set the function for getting the system time. This is mostly used for * unit testing to provide a fixed / shifted time stamp. Setting the * value to NULL restores the original function, that is, 'time()', * which is also the automatic default. */ extern systime_func_ptr ntpcal_set_timefunc(systime_func_ptr); /* * days-of-week */ #define CAL_SUNDAY 0 #define CAL_MONDAY 1 #define CAL_TUESDAY 2 #define CAL_WEDNESDAY 3 #define CAL_THURSDAY 4 #define CAL_FRIDAY 5 #define CAL_SATURDAY 6 #define CAL_SUNDAY7 7 /* also sunday */ /* * Days in each month. 30 days hath September... */ #define JAN 31 #define FEB 28 #define FEBLEAP 29 #define MAR 31 #define APR 30 #define MAY 31 #define JUN 30 #define JUL 31 #define AUG 31 #define SEP 30 #define OCT 31 #define NOV 30 #define DEC 31 /* * We deal in a 4 year cycle starting at March 1, 1900. We assume * we will only want to deal with dates since then, and not to exceed * the rollover day in 2036. */ #define SECSPERMIN (60) /* seconds per minute */ #define MINSPERHR (60) /* minutes per hour */ #define HRSPERDAY (24) /* hours per day */ #define DAYSPERWEEK (7) /* days per week */ #define DAYSPERYEAR (365) /* days per year */ #define SECSPERHR (SECSPERMIN * MINSPERHR) #define SECSPERDAY (SECSPERHR * HRSPERDAY) #define SECSPERWEEK (DAYSPERWEEK * SECSPERDAY) #define SECSPERYEAR (365 * SECSPERDAY) /* regular year */ #define SECSPERLEAPYEAR (366 * SECSPERDAY) /* leap year */ #define SECSPERAVGYEAR 31556952 /* mean year length over 400yrs */ /* * Gross hacks. I have illicit knowlege that there won't be overflows * here, the compiler often can't tell this. */ #define TIMES60(val) ((((val)<<4) - (val))<<2) /* *(16 - 1) * 4 */ #define TIMES24(val) (((val)<<4) + ((val)<<3)) /* *16 + *8 */ #define TIMES7(val) (((val)<<3) - (val)) /* *8 - *1 */ #define TIMESDPERC(val) (((val)<<10) + ((val)<<8) \ + ((val)<<7) + ((val)<<5) \ + ((val)<<4) + ((val)<<2) + (val)) /* *big* hack */ extern const char * const months[12]; extern const char * const daynames[7]; extern void caljulian (uint32_t, struct calendar *); extern uint32_t caltontp (const struct calendar *); /* * Convert between 'time_t' and 'vint64' */ extern vint64 time_to_vint64(const time_t *); extern time_t vint64_to_time(const vint64 *); /* * Get the build date & time. ATTENTION: The time zone is not specified! * This depends entirely on the C compilers' capabilities to properly * expand the '__TIME__' and '__DATE__' macros, as required by the C * standard. */ extern int ntpcal_get_build_date(struct calendar * /* jd */); /* * Convert a timestamp in NTP scale to a time_t value in the UN*X * scale with proper epoch unfolding around a given pivot or the * current system time. */ extern vint64 ntpcal_ntp_to_time(uint32_t /* ntp */, const time_t * /* pivot */); /* * Convert a timestamp in NTP scale to a 64bit seconds value in the NTP * scale with proper epoch unfolding around a given pivot or the current * system time. * Note: The pivot must be given in UN*X time scale! */ extern vint64 ntpcal_ntp_to_ntp(uint32_t /* ntp */, const time_t * /* pivot */); /* * Split a time stamp in seconds into elapsed days and elapsed seconds * since midnight. */ extern ntpcal_split ntpcal_daysplit(const vint64 *); /* * Merge a number of days and a number of seconds into seconds, * expressed in 64 bits to avoid overflow. */ extern vint64 ntpcal_dayjoin(int32_t /* days */, int32_t /* seconds */); /* Get the number of leap years since epoch for the number of elapsed * full years */ extern int32_t ntpcal_leapyears_in_years(int32_t /* years */); /* * Convert elapsed years in Era into elapsed days in Era. */ extern int32_t ntpcal_days_in_years(int32_t /* years */); /* * Convert a number of elapsed month in a year into elapsed days * in year. * * The month will be normalized, and 'res.hi' will contain the * excessive years that must be considered when converting the years, * while 'res.lo' will contain the days since start of the * year. (Expect the resulting days to be negative, with a positive * excess! But then, we need no leap year flag, either...) */ extern ntpcal_split ntpcal_days_in_months(int32_t /* months */); /* * Convert ELAPSED years/months/days of gregorian calendar to elapsed * days in Gregorian epoch. No range checks done here! */ extern int32_t ntpcal_edate_to_eradays(int32_t /* years */, int32_t /* months */, int32_t /* mdays */); /* * Convert a time spec to seconds. No range checks done here! */ extern int32_t ntpcal_etime_to_seconds(int32_t /* hours */, int32_t /* minutes */, int32_t /* seconds */); /* * Convert ELAPSED years/months/days of gregorian calendar to elapsed * days in year. * * Note: This will give the true difference to the start of the given year, * even if months & days are off-scale. */ extern int32_t ntpcal_edate_to_yeardays(int32_t /* years */, int32_t /* months */, int32_t /* mdays */); /* * Convert the date part of a 'struct tm' (that is, year, month, * day-of-month) into the RataDie of that day. */ extern int32_t ntpcal_tm_to_rd(const struct tm * /* utm */); /* * Convert the date part of a 'struct calendar' (that is, year, month, * day-of-month) into the RataDie of that day. */ extern int32_t ntpcal_date_to_rd(const struct calendar * /* jt */); /* * Given the number of elapsed days in the calendar era, split this * number into the number of elapsed years in 'res.quot' and the * number of elapsed days of that year in 'res.rem'. * * if 'isleapyear' is not NULL, it will receive an integer that is 0 * for regular years and a non-zero value for leap years. * * The input is limited to [-2^30, 2^30-1]. If the days exceed this * range, errno is set to EDOM and the result is saturated. */ extern ntpcal_split ntpcal_split_eradays(int32_t /* days */, int/*BOOL*/ * /* isleapyear */); /* * Given a number of elapsed days in a year and a leap year indicator, * split the number of elapsed days into the number of elapsed months * in 'res.quot' and the number of elapsed days of that month in * 'res.rem'. */ extern ntpcal_split ntpcal_split_yeardays(int32_t /* eyd */, int/*BOOL*/ /* isleapyear */); /* * Convert a RataDie number into the date part of a 'struct * calendar'. Return 0 if the year is regular year, !0 if the year is * a leap year. */ extern int/*BOOL*/ ntpcal_rd_to_date(struct calendar * /* jt */, int32_t /* rd */); /* * Convert a RataDie number into the date part of a 'struct * tm'. Return 0 if the year is regular year, !0 if the year is a leap * year. */ extern int/*BOOL*/ ntpcal_rd_to_tm(struct tm * /* utm */, int32_t /* rd */); /* * Take a value of seconds since midnight and split it into hhmmss in * a 'struct calendar'. Return excessive days. */ extern int32_t ntpcal_daysec_to_date(struct calendar * /* jt */, int32_t /* secs */); /* * Take the time part of a 'struct calendar' and return the seconds * since midnight. */ extern int32_t ntpcal_date_to_daysec(const struct calendar *); /* * Take a value of seconds since midnight and split it into hhmmss in * a 'struct tm'. Return excessive days. */ extern int32_t ntpcal_daysec_to_tm(struct tm * /* utm */, int32_t /* secs */); extern int32_t ntpcal_tm_to_daysec(const struct tm * /* utm */); /* * convert a year number to rata die of year start */ extern int32_t ntpcal_year_to_ystart(int32_t /* year */); /* * For a given RataDie, get the RataDie of the associated year start, * that is, the RataDie of the last January,1st on or before that day. */ extern int32_t ntpcal_rd_to_ystart(int32_t /* rd */); /* * convert a RataDie to the RataDie of start of the calendar month. */ extern int32_t ntpcal_rd_to_mstart(int32_t /* year */); extern int ntpcal_daysplit_to_date(struct calendar * /* jt */, const ntpcal_split * /* ds */, int32_t /* dof */); extern int ntpcal_daysplit_to_tm(struct tm * /* utm */, const ntpcal_split * /* ds */, int32_t /* dof */); extern int ntpcal_time_to_date(struct calendar * /* jd */, const vint64 * /* ts */); extern int32_t ntpcal_periodic_extend(int32_t /* pivot */, int32_t /* value */, int32_t /* cycle */); extern int ntpcal_ntp64_to_date(struct calendar * /* jd */, const vint64 * /* ntp */); extern int ntpcal_ntp_to_date(struct calendar * /* jd */, uint32_t /* ntp */, const time_t * /* pivot */); extern vint64 ntpcal_date_to_ntp64(const struct calendar * /* jd */); extern uint32_t ntpcal_date_to_ntp(const struct calendar * /* jd */); extern time_t ntpcal_date_to_time(const struct calendar * /* jd */); /* * ISO week-calendar conversions */ extern int32_t isocal_weeks_in_years(int32_t /* years */); /* * The input is limited to [-2^30, 2^30-1]. If the weeks exceed this * range, errno is set to EDOM and the result is saturated. */ extern ntpcal_split isocal_split_eraweeks(int32_t /* weeks */); extern int isocal_ntp64_to_date(struct isodate * /* id */, const vint64 * /* ntp */); extern int isocal_ntp_to_date(struct isodate * /* id */, uint32_t /* ntp */, const time_t * /* pivot */); extern vint64 isocal_date_to_ntp64(const struct isodate * /* id */); extern uint32_t isocal_date_to_ntp(const struct isodate * /* id */); /* * day-of-week calculations * * Given a RataDie and a day-of-week, calculate a RDN that is reater-than, * greater-or equal, closest, less-or-equal or less-than the given RDN * and denotes the given day-of-week */ extern int32_t ntpcal_weekday_gt(int32_t /* rdn */, int32_t /* dow */); extern int32_t ntpcal_weekday_ge(int32_t /* rdn */, int32_t /* dow */); extern int32_t ntpcal_weekday_close(int32_t /* rdn */, int32_t /* dow */); extern int32_t ntpcal_weekday_le(int32_t /* rdn */, int32_t /* dow */); extern int32_t ntpcal_weekday_lt(int32_t /* rdn */, int32_t /* dow */); /* * Additional support stuff for Ed Rheingold's calendrical calculations */ /* * Start day of NTP time as days past the imaginary date 12/1/1 BC. * (This is the beginning of the Christian Era, or BCE.) */ #define DAY_NTP_STARTS 693596 /* * Start day of the UNIX epoch. This is the Rata Die of 1970-01-01. */ #define DAY_UNIX_STARTS 719163 /* * Difference between UN*X and NTP epoch (25567). */ #define NTP_TO_UNIX_DAYS (DAY_UNIX_STARTS - DAY_NTP_STARTS) /* * Days in a normal 4 year leap year calendar cycle (1461). */ #define GREGORIAN_NORMAL_LEAP_CYCLE_DAYS (3 * 365 + 366) /* * Days in a normal 100 year leap year calendar (36524). We lose a * leap day in years evenly divisible by 100 but not by 400. */ #define GREGORIAN_NORMAL_CENTURY_DAYS \ (25 * GREGORIAN_NORMAL_LEAP_CYCLE_DAYS - 1) /* * The Gregorian calendar is based on a 400 year cycle. This is the * number of days in each cycle (146097). We gain a leap day in years * divisible by 400 relative to the "normal" century. */ #define GREGORIAN_CYCLE_DAYS (4 * GREGORIAN_NORMAL_CENTURY_DAYS + 1) /* * Number of weeks in 400 years (20871). */ #define GREGORIAN_CYCLE_WEEKS (GREGORIAN_CYCLE_DAYS / 7) #define is_leapyear(y) (!((y) % 4) && !(!((y) % 100) && (y) % 400)) #endif