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SUBROUTINE ju2ymds (julian, year, month, day, sec) |
SUBROUTINE ju2ymds (julian, year, month, day, sec) |
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use calendar, only: un_jour |
! This subroutine computes from the julian day the year, |
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USE ju2ymds_internal_m, ONLY: ju2ymds_internal |
! month, day and seconds |
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! In 1968 in a letter to the editor of Communications of the ACM |
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! (CACM, volume 11, number 10, October 1968, p.657) Henry F. Fliegel |
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! and Thomas C. Van Flandern presented such an algorithm. |
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! See also: http://www.magnet.ch/serendipity/hermetic/cal_stud/jdn.htm |
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! In the case of the Gregorian calendar we have chosen to use |
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! the Lilian day numbers. This is the day counter which starts |
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! on the 15th October 1582. This is the day at which Pope |
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! Gregory XIII introduced the Gregorian calendar. |
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! Compared to the true Julian calendar, which starts some 7980 |
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! years ago, the Lilian days are smaler and are dealt with easily |
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! on 32 bit machines. With the true Julian days you can only the |
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! fraction of the day in the real part to a precision of a 1/4 of |
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! a day with 32 bits. |
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use calendar, only: un_jour, lock_unan |
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use ioconf_calendar_m, only: mon_len, un_an |
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REAL, INTENT(IN):: julian |
REAL, INTENT(IN):: julian |
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INTEGER, INTENT(OUT):: year, month, day |
INTEGER, INTENT(OUT):: year, month, day |
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REAL, INTENT(OUT):: sec |
REAL, INTENT(OUT):: sec |
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INTEGER:: julian_day |
! Local: |
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REAL:: julian_sec |
INTEGER:: l, n, i, jd, j, d, m, y, ml |
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INTEGER:: add_day |
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!-------------------------------------------------------------------- |
!-------------------------------------------------------------------- |
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julian_day = INT(julian) |
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julian_sec = (julian-julian_day)*un_jour |
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CALL ju2ymds_internal(julian_day, julian_sec, year, month, day, sec) |
jd = INT(julian) |
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sec = (julian - jd) * un_jour |
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lock_unan = .TRUE. |
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IF (sec > un_jour) THEN |
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add_day = INT(sec / un_jour) |
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sec = sec - add_day * un_jour |
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jd = jd+add_day |
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ENDIF |
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! Gregorian |
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IF ( (un_an > 365.0).AND.(un_an < 366.0) ) THEN |
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jd = jd+2299160 |
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l = jd+68569 |
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n = (4*l)/146097 |
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l = l-(146097*n+3)/4 |
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i = (4000*(l+1))/1461001 |
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l = l-(1461*i)/4+31 |
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j = (80*l)/2447 |
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d = l-(2447*j)/80 |
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l = j/11 |
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m = j+2-(12*l) |
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y = 100*(n-49)+i+l |
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! No leap or All leap |
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ELSE IF (ABS(un_an-365.0) <= EPSILON(un_an) .OR. & |
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& ABS(un_an-366.0) <= EPSILON(un_an) ) THEN |
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y = jd/INT(un_an) |
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l = jd-y*INT(un_an) |
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m = 1 |
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ml = 0 |
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DO WHILE (ml+mon_len(m) <= l) |
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ml = ml+mon_len(m) |
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m = m+1 |
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ENDDO |
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d = l-ml+1 |
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! others |
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ELSE |
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ml = INT(un_an)/12 |
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y = jd/INT(un_an) |
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l = jd-y*INT(un_an) |
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m = (l/ml)+1 |
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d = l-(m-1)*ml+1 |
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ENDIF |
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day = d |
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month = m |
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year = y |
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END SUBROUTINE ju2ymds |
END SUBROUTINE ju2ymds |
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