ユリウス日と西暦の変換

caldat.f90

ユリウス日→西暦

subroutine caldat(JULIAN,IYYY,MONTH,DD)

! Description:

! Author: am

! Host: aofd30

! Directory: /work2/am/12.Work11/75.Mitsui/52.Vertical_Profile/src

! Revision history:

!  This file is created by /usr/local/mybin/nff.sh at 11:00 on 11-01-2011.

!  use

!  implicit none

      INTEGER,intent(in):: JULIAN

      integer,intent(out)::IYYY,MONTH,DD

! NAME   IN/OUT DESCRIPTION

! JULIAN   I    THE JULIAN DAY

! IYYY     O    THE YEAR

! MONTH    O    THE MONTH (1 TO 12)

! DD       O    THE DAY OF THE MONTH

      INTEGER IGREG

      PARAMETER (IGREG=2299161)

      INTEGER JALPHA,JA,JB,JC,JD,JE

      IF (JULIAN .GE. IGREG) THEN

        JALPHA = INT(((JULIAN - 1867216) - 0.25)/36524.25)

        JA = JULIAN + 1 + JALPHA - INT(0.25*JALPHA)

      ELSE

        JA = JULIAN

      ENDIF

      JB = JA + 1524

      JC = INT(6680. + ((JB - 2439870) - 122.1)/365.25)

      JD = 365*JC + INT(0.25*JC)

      JE = INT((JB - JD)/30.6001)

      DD = JB - JD - INT(30.6001*JE)

      MONTH = JE - 1

      IF (MONTH .GT. 12) MONTH = MONTH - 12

      IYYY = JC - 4715

      IF (MONTH .GT. 2) IYYY = IYYY - 1

      IF (IYYY .LE. 0) IYYY = IYYY - 1

      RETURN

end subroutine caldat

julday.f90

西暦→ユリウス日

INTEGER FUNCTION JULDAY(IYYY,MONTH,DD)

      INTEGER,intent(inout):: IYYY,MONTH,DD

! NAME   IN/OUT DESCRIPTION

! IYYY     I    YEAR

! MONTH    I    MONTH (1 TO 12)

! DD       I    DAY OF MONTH

      INTEGER IGREG

      PARAMETER (IGREG = 15 + 31*(10 + 12*1582))

      INTEGER JY,JM,JA

      IF (IYYY .LT. 0) IYYY = IYYY + 1

      IF (MONTH .GT. 2) THEN

        JY = IYYY

        JM = MONTH + 1

      ELSE

        JY = IYYY - 1

        JM = MONTH + 13

      ENDIF

      JULDAY = INT(365.25*JY) + INT(30.6001*JM) + DD + 1720995

      IF (DD + 31*(MONTH + 12*IYYY) .GE. IGREG) THEN

        JA = INT(0.01*JY)

        JULDAY = JULDAY + 2 - JA + INT(0.25*JA)

      ENDIF

      RETURN

end function julday