/contrib/ntp/include/ntp_calendar.h
https://bitbucket.org/freebsd/freebsd-head/ · C++ Header · 112 lines · 55 code · 17 blank · 40 comment · 5 complexity · 99d272aa103d7893afa86768f72e9df3 MD5 · raw file
- /*
- * ntp_calendar.h - definitions for the calendar time-of-day routine
- */
- #ifndef NTP_CALENDAR_H
- #define NTP_CALENDAR_H
- #include "ntp_types.h"
- struct calendar {
- u_short year; /* year (A.D.) */
- u_short yearday; /* day of year, 1 = January 1 */
- u_char month; /* month, 1 = January */
- u_char monthday; /* day of month */
- u_char hour; /* hour of day, midnight = 0 */
- u_char minute; /* minute of hour */
- u_char second; /* second of minute */
- };
- /*
- * 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 DAYSPERYEAR (365) /* days per year */
- #define SECSPERDAY (SECSPERMIN*MINSPERHR*HRSPERDAY)
- #define SECSPERYEAR (365 * SECSPERDAY) /* regular year */
- #define SECSPERLEAPYEAR (366 * SECSPERDAY) /* leap year */
- #define MAR1900 ((JAN+FEB) * SECSPERDAY) /* no leap year in 1900 */
- #define DAYSPERCYCLE (365+365+365+366) /* 3 normal years plus leap */
- #define SECSPERCYCLE (DAYSPERCYCLE*SECSPERDAY)
- #define YEARSPERCYCLE 4
- /*
- * 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 */
- /*
- * Another big hack. Cycle 22 started on March 1, 1988. This is
- * STARTCYCLE22 seconds after the start of cycle 0.
- */
- #define CYCLE22 (22)
- #define STARTCYCLE22 (u_long)(0xa586b500) /* 2777068800 */
- #define MAR1988 (u_long)(STARTCYCLE22 + (u_long)MAR1900)
- /*
- * The length of January + February in leap and non-leap years.
- */
- #define JANFEBNOLEAP ((JAN+FEB) * SECSPERDAY)
- #define JANFEBLEAP ((JAN+FEBLEAP) * SECSPERDAY)
- extern void caljulian P((u_long, struct calendar *));
- extern u_long caltontp P((const struct calendar *));
- /*
- * Additional support stuff for Ed Rheingold's calendrical calculations
- */
- /*
- * Start day of NTP time as days past the imaginary date 12/1/1 BC.
- * P((This is the beginning of the Christian Era, or BCE.))
- */
- #define DAY_NTP_STARTS 693596
- /*
- * The Gregorian calendar is based on a 400 year cycle. This is the number
- * of days in each cycle.
- */
- #define GREGORIAN_CYCLE_DAYS 146097
- /*
- * Days in a normal 100 year leap year calendar. We lose a leap year day
- * in years evenly divisible by 100 but not by 400.
- */
- #define GREGORIAN_NORMAL_CENTURY_DAYS 36524
- /*
- * Days in a normal 4 year leap year calendar cycle.
- */
- #define GREGORIAN_NORMAL_LEAP_CYCLE_DAYS 1461
- #define is_leapyear(y) (y%4 == 0 && !(y%100 == 0 && !(y%400 == 0)))
- #endif