55 lines
1.1 KiB
C
55 lines
1.1 KiB
C
/* 19950925 */
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#include "datetime.h"
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void datetime_tai(dt,t)
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struct datetime *dt;
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datetime_sec t;
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{
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int day;
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int tod;
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int year;
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int yday;
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int wday;
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int mon;
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tod = t % 86400;
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day = t / 86400;
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if (tod < 0) { tod += 86400; --day; }
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dt->hour = tod / 3600;
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tod %= 3600;
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dt->min = tod / 60;
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dt->sec = tod % 60;
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wday = (day + 4) % 7; if (wday < 0) wday += 7;
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dt->wday = wday;
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day -= 11017;
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/* day 0 is march 1, 2000 */
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year = 5 + day / 146097;
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day = day % 146097; if (day < 0) { day += 146097; --year; }
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/* from now on, day is nonnegative */
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year *= 4;
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if (day == 146096) { year += 3; day = 36524; }
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else { year += day / 36524; day %= 36524; }
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year *= 25;
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year += day / 1461;
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day %= 1461;
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year *= 4;
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yday = (day < 306);
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if (day == 1460) { year += 3; day = 365; }
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else { year += day / 365; day %= 365; }
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yday += day;
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day *= 10;
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mon = (day + 5) / 306;
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day = day + 5 - 306 * mon;
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day /= 10;
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if (mon >= 10) { yday -= 306; ++year; mon -= 10; }
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else { yday += 59; mon += 2; }
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dt->yday = yday;
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dt->year = year - 1900;
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dt->mon = mon;
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dt->mday = day + 1;
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}
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