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Annotation of coherent/g/usr/lib/misc/tmtojd.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Year, month, day to julian day in integers.
        !             3:  * Algorithm from Duffett-Smith, Practical Astronomy With Your Calculator
        !             4:  * Also Meeus, Astronomical Formulae for Calculators
        !             5:  */
        !             6: #include "local_misc.h"
        !             7: 
        !             8: /* Pack year, month, and day into long package for easy compares */
        !             9: #define pymd(y,m,d)    (((long)(y)<<16)|((m)<<8)|(d))
        !            10: 
        !            11: jday_t
        !            12: tm_to_jday(tp)
        !            13: register tm_t *tp;
        !            14: {
        !            15:        register int y, m, B;
        !            16:        register long C, D;
        !            17:        jday_t jd;
        !            18: 
        !            19:        y = tp->tm_year + 1900;
        !            20:        m = tp->tm_mon + 1;
        !            21:        if (m <= 2) {
        !            22:                y -= 1; m += 12;
        !            23:        }
        !            24:        /* Gregorian correction */
        !            25:        if (pymd(y, m, tp->tm_mday) > pymd(1582, 10, 15)) {
        !            26:                B = 2 - (y/100) + (y/400);
        !            27:        } else
        !            28:                B = 0;
        !            29:        C = (y * 36525L) / 100;
        !            30:        D = ((m + 1) * 306001L) / 10000;
        !            31:        jd.j_d = tp->tm_mday + B + C + D + 1720994L;
        !            32:        jd.j_s = tp->tm_sec + 60L * (tp->tm_min + 60 * tp->tm_hour);
        !            33:        if ((jd.j_s += 86400L/2) >= 86400L) {
        !            34:                jd.j_s -= 86400L; jd.j_d += 1;
        !            35:        }
        !            36:        return jd;
        !            37: }

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