w3timemd.F90

Go to the documentation of this file.

#include "w3macros.h"
!/ ------------------------------------------------------------------- /
MODULE w3timemd
  !/
  !/                  +-----------------------------------+
  !/                  | WAVEWATCH III           NOAA/NCEP |
  !/                  |           H. L. Tolman            |
  !/                  |                        FORTRAN 90 |
  !/                  | Last update :         23-Feb-2024 |
  !/                  +-----------------------------------+
  !/
  !/    Copyright 2009 National Weather Service (NWS),
  !/       National Oceanic and Atmospheric Administration.  All rights
  !/       reserved.  WAVEWATCH III is a trademark of the NWS.
  !/       No unauthorized use without permission.
  !/
  !  1. Purpose :
  !
  !     Routines for management of date and time.
  !
  !  2. Variables and types :
  !
  !      Name      Type  Scope    Description
  !     ----------------------------------------------------------------
  !      PRFTB     I.A.  Private  Base time for profiling.
  !      FLPROF    Log.  Private  Flag for profiling initialization.
  !     ----------------------------------------------------------------
  !
  !  3. Subroutines and functions :
  !
  !      Name      Type  Scope    Description
  !     ----------------------------------------------------------------
  !      TICK21    Subr. Public   Increment a date and time array with
  !                               a given number of seconds.
  !      IYMD21    I.F.  TICK21   Date increment function.
  !      DSEC21    R.F.  Public   Calculate the difference in seconds
  !                               between two data/time arrays.
  !      TDIFF     R.F.  Public   Calculate the difference in seconds
  !                               between two date/time arrays that
  !                               were generated from DATE_AND_TIME
  !      MYMD21    I.F.  DSEC21   Julian date function.
  !      STME21    Subr. Public   Converts integer time to string.
  !      JULDAY    I.F.  Public   Julian date function
  !      CALDAT    Subr. Public   Transform Julian day to date
  !      PRINIT    Subr. Public   Initialize profiling.
  !      PRTIME    Subr. Public   Get profiling time.
  !      D2J       Subr. Public   Convert date array to julian date
  !      J2D       Subr. Public   Convert julian date to date array
  !      T2D       Subr. Public   Convert time array to date array
  !      TSUB      I.D.  Public   Substract two time arrays in days
  !      TSUBSEC   I.D.  Public   Substract two time arrays in seconds
  !      U2D       Subr. Public   Convert time units attribute to date array
  !      T2ISO     Subr. Public   Convert time array to ISO time string
  !     ----------------------------------------------------------------
  !
  !  4. Subroutines and functions used :
  !
  !      Name      Type  Module   Description
  !     ----------------------------------------------------------------
  !      STRACE    Subr. W3SERVMD Subroutine tracing.
  !     ----------------------------------------------------------------
  !
  !  5. Remarks :
  !
  !  6. Switches :
  !
  !  7. Source code :
  !
  !/ ------------------------------------------------------------------- /
  !/
#ifdef W3_S
  USE w3servmd, ONLY: strace
#endif
  !
  PUBLIC
  !
  INTEGER, PRIVATE        :: PRFTB(8)
  LOGICAL, PRIVATE        :: FLPROF = .false.
  CHARACTER, PUBLIC       :: caltype*8
  !
CONTAINS
  !/ ------------------------------------------------------------------- /
  SUBROUTINE tick21 ( TIME, DTIME )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           H. L. Tolman            |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         29-Nov-1999 |
    !/                  +-----------------------------------+
    !/                                Based on TICK of the GLA GCM.
    !/
    !/    23-Mar-1993 : Final FORTRAN 77                    ( version 1.18 )
    !/    29-Nov-1999 : Upgrade to FORTRAN 90               ( version 2.00 )
    !/
    !  1. Purpose :
    !
    !     Updates time information, DTIME=0 converts to "legal" time.
    !     Goes into the 21st century.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       TIME    I.A.  I/O  (1) Current date in YYYYMMDD format.
    !                          (2) Current time in HHMMSS format.
    !       DTIME   Real   I   Time step in seconds.
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !      IYMD21    Func. Internal Increment date in YYYYMMDD format.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any other routine.
    !
    !  8. Structure :
    !
    !     See source code.
    !
    !  9. Switches :
    !
    !     !/S  Enable subroutine tracing using STRACE.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(INOUT)  :: TIME(2)
    REAL, INTENT(IN)        :: DTIME
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: NYMD, NHMS, NSEC
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'TICK21')
#endif
    !
    ! Zero increment: get "legal" date
    !
    nymd   = time(1)
    nhms   = time(2)
    IF (dtime.EQ.0.) THEN
      nymd = iymd21(nymd,-1)
      nymd = iymd21(nymd, 1)
    END IF
    !
    ! Convert and increment time :
    !
    nsec = nhms/10000*3600 + mod(nhms,10000)/100* 60 +        &
         mod(nhms,100) + nint(dtime)
    !
    ! Check change of date :
    !
100 CONTINUE
    IF (nsec.GE.86400)  THEN
      nsec = nsec - 86400
      nymd = iymd21(nymd,1)
      GOTO 100
    END IF
    !
200 CONTINUE
    IF (nsec.LT.00000)  THEN
      nsec = 86400 + nsec
      nymd = iymd21(nymd,-1)
      GOTO 200
    END IF
    !
    nhms = nsec/3600*10000 + mod(nsec,3600)/60*100 + mod(nsec,60)
    !
    time(1) = nymd
    time(2) = nhms
    !
    RETURN
    !/
    !/ Internal function IYMD21 ------------------------------------------ /
    !/
  CONTAINS
    !/ ------------------------------------------------------------------- /
    INTEGER FUNCTION iymd21 ( NYMD ,M )
      !/
      !/                  +-----------------------------------+
      !/                  | WAVEWATCH III           NOAA/NCEP |
      !/                  |           H. L. Tolman            |
      !/                  |                        FORTRAN 90 |
      !/                  | Last update :         18-Jun-2020 |
      !/                  +-----------------------------------+
      !/                                Based on INCYMD of the GLA GCM.
      !/
      !/    18-Oct-1998 : Final FORTRAN 77                    ( version 1.18 )
      !/    29-Nov-1999 : Upgrade to FORTRAN 90               ( version 2.00 )
      !/    10-Jan-2017 : Add NOLEAP option, 365 day calendar ( version 6.00 )
      !/    18-Jun-2020 : Add 360-day calendar option         ( version 7.08 )
      !/
      !  1. Purpose :
      !
      !     Increment date in YYYYMMDD format by +/- 1 day.
      !
      !  3. Parameters :
      !
      !     Parameter list
      !     ----------------------------------------------------------------
      !       NYMD    Int.   I   Old date in YYMMDD format.
      !       M       Int.   I   +/- 1 (Day adjustment)
      !     ----------------------------------------------------------------
      !
      !  4. Subroutines used :
      !
      !      Name      Type  Module   Description
      !     ----------------------------------------------------------------
      !      STRACE    Subr. W3SERVMD Subroutine tracing.
      !     ----------------------------------------------------------------
      !
      !  5. Called by :
      !
      !     Any subroutine.
      !
      !  8. Structure :
      !
      !     See source code.
      !
      !  9. Switches :
      !
      !     !/S  Enable subroutine tracing using STRACE.
      !
      ! 10. Source code :
      !
      !/ ------------------------------------------------------------------- /
      !/
      IMPLICIT NONE
      !/
      !/ ------------------------------------------------------------------- /
      !/ Parameter list
      !/
      INTEGER, INTENT(IN)     :: nymd, m
      !/
      !/ ------------------------------------------------------------------- /
      !/ Local parameters
      !/
      INTEGER                 :: ny, nm, nd
      INTEGER, SAVE           :: ndpm(12)
#ifdef W3_S
      INTEGER, SAVE           :: ient = 0
#endif
      LOGICAL                 :: leap
      !/
      !/ ------------------------------------------------------------------- /
      !/
#ifdef W3_S
      CALL strace (ient, 'IYMD21')
#endif
      !
      ! Declare the number of days in month depending on calendar
      !
      IF (trim(caltype) .EQ. '360_day' ) THEN
        ndpm=(/ 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30 /)
      ELSE
        ndpm=(/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
      END IF
      !
      ! "Unpack" and increment date :
      !
      ny   = nymd / 10000
      nm   = mod(nymd,10000) / 100
      nm   = min( 12 , max(1,nm) )
      nd   = mod(nymd,100) + m
      ! Add override for simulations with no leap years
      IF (trim(caltype) .EQ. 'standard' ) THEN
        leap = mod(ny,400).EQ.0 .OR.                           &
             ( mod(ny,4).EQ.0 .AND. mod(ny,100).NE.0 )
      ELSE
        leap = .false.
      END IF
      !
      ! M = -1, change month if necessary :
      !
      IF (nd.EQ.0) THEN
        nm   = nm - 1
        IF (nm.EQ.0) THEN
          nm   = 12
          ny   = ny - 1
        ENDIF
        nd   = ndpm(nm)
        IF (nm.EQ.2 .AND. leap)  nd = 29
      END IF
      !
      ! M = 1, leap year
      !
      IF (nd.EQ.29 .AND. nm.EQ.2 .AND. leap)  GO TO 20
      !
      !        next month
      !
      IF (nd.GT.ndpm(nm)) THEN
        nd = 1
        nm = nm + 1
        IF (nm.GT.12) THEN
          nm = 1
          ny = ny + 1
        ENDIF
      END IF
      !
20    CONTINUE
      iymd21 = ny*10000 + nm*100 + nd
      !
      RETURN
      !/
      !/ End of IYMD21 ----------------------------------------------------- /
      !/
    END FUNCTION iymd21
    !/
    !/ End of TICK21 ----------------------------------------------------- /
    !/
  END SUBROUTINE tick21
  !/ ------------------------------------------------------------------- /
  REAL function dsec21 ( time1, time2 )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           H. L. Tolman            |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         18-Jun-2020 |
    !/                  +-----------------------------------+
    !/
    !/    23-Mar-1993 : Final FORTRAN 77                    ( version 1.18 )
    !/    29-Nov-1999 : Upgrade to FORTRAN 90               ( version 2.00 )
    !/    05-Jan-2001 : Y2K leap year error correction.     ( version 2.05 )
    !/    18-Jun-2020 : Add 360-day calendar support        ( version 7.08 )
    !/
    !/
    !  1. Purpose :
    !
    !     Calculate the time difference in seconds between two times in
    !     YYMMD HHMMMSS formats.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       TIMEn   I.A.   I   Times, TIMEn(1) is date in YYYYMMDD format,
    !                          TIMEn(2) is time in HHMMSS format.
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !      MYMD21    Func. Internal Calculate Julian date.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any routine.
    !
    !  7. Remarks :
    !
    !  8. Structure :
    !
    !     See source code.
    !
    !  9. Switches :
    !
    !     !/S  Enable subroutine tracing using STRACE.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(IN)     :: time1(2), time2(2)
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: ny1, nd1, ny2, nd2, ns1, ns2, ns,   &
         nd, nst
#ifdef W3_S
    INTEGER, SAVE           :: ient = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'DSEC21')
#endif
    !
    ! Convert dates and times :
    !
    ny1    = time1(1) / 10000
    nd1    = mymd21( time1(1) )
    ns1    = time1(2)/10000*3600 + mod(time1(2),10000)/100*60 + &
         mod(time1(2),100)
    !
    ny2    = time2(1) / 10000
    nd2    = mymd21( time2(1) )
    ns2    = time2(2)/10000*3600 + mod(time2(2),10000)/100*60 + &
         mod(time2(2),100)
    !
    ! Number of days and seconds in difference :
    !
    nd     = nd2 - nd1
    !
    IF ( ny1 .NE. ny2 ) THEN
      nst    = sign( 1 , ny2-ny1 )
100   CONTINUE
      IF (ny1.EQ.ny2) GOTO 200
      IF (nst.GT.0) THEN
        ny2    = ny2 - 1
        IF (trim(caltype) .EQ. '360_day' ) THEN
          nd     = nd  + mymd21( ny2*10000 + 1230 )
        ELSE
          nd     = nd  + mymd21( ny2*10000 + 1231 )
        END IF
      ELSE
        IF (trim(caltype) .EQ. '360_day' ) THEN
          nd     = nd  - mymd21( ny2*10000 + 1230 )
        ELSE
          nd     = nd  - mymd21( ny2*10000 + 1231 )
        END IF
        ny2    = ny2 + 1
      ENDIF
      GOTO 100
200   CONTINUE
    END IF
    !
    ns     = ns2 - ns1
    !
    ! Output of time difference :
    !
    dsec21 = real(ns) + 86400.*real(nd)
    !
    RETURN
    !/
    !/ Internal function MYMD21 ------------------------------------------ /
    !/
  CONTAINS
    !/ ------------------------------------------------------------------- /
    INTEGER FUNCTION mymd21 ( NYMD )
      !/
      !/                  +-----------------------------------+
      !/                  | WAVEWATCH III           NOAA/NCEP |
      !/                  |           H. L. Tolman            |
      !/                  |                        FORTRAN 90 |
      !/                  | Last update :         18-Jun-2020 |
      !/                  +-----------------------------------+
      !/                                Based on MODYMD of the GLA GCM.
      !/
      !/    19-Oct-1998 : Final FORTRAN 77                    ( version 1.18 )
      !/    29-Nov-1999 : Upgrade to FORTRAN 90               ( version 2.00 )
      !/    10-Jan-2017 : Add NOLEAP option, 365 day calendar ( version 6.01 )
      !/    18-Jun-2020 : Add 360-day calendar support        ( version 7.08 )
      !/
      !  1. Purpose :
      !
      !     Convert date in YYMMDD format to julian date.
      !
      !  3. Parameters :
      !
      !     Parameter list
      !     ----------------------------------------------------------------
      !       NYMD    Int.   I   Date in YYMMDD format.
      !     ----------------------------------------------------------------
      !
      !  4. Subroutines used :
      !
      !      Name      Type  Module   Description
      !     ----------------------------------------------------------------
      !      STRACE    Subr. W3SERVMD Subroutine tracing.
      !     ----------------------------------------------------------------
      !
      !  5. Called by :
      !
      !     Any subroutine.
      !
      !  8. Structure :
      !
      !     See source code.
      !
      !  9. Switches :
      !
      !     !/S  Enable subroutine tracing using STRACE.
      !
      ! 10. Source code :
      !
      !/ ------------------------------------------------------------------- /
      !/
      IMPLICIT NONE
      !/
      !/ ------------------------------------------------------------------- /
      !/ Parameter list
      !/
      INTEGER, INTENT(IN)     :: nymd
      !/
      !/ ------------------------------------------------------------------- /
      !/ Local parameters
      !/
      INTEGER                 :: ny, nm, nd
      INTEGER, SAVE           :: ndpm(12)
#ifdef W3_S
      INTEGER, SAVE           :: ient = 0
#endif
      LOGICAL                 :: leap
      !/
      !/ ------------------------------------------------------------------- /
      !/
#ifdef W3_S
      CALL strace (ient, 'MYMD21')
#endif
      !
      ! Declare the number of days in month depending on calendar
      !
      IF (trim(caltype) .EQ. '360_day' ) THEN
        ndpm=(/ 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30 /)
      ELSE
        ndpm=(/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
      END IF
      !
      ! "Unpack" and increment date :
      !
      ny   = nymd / 10000
      nm   = mod(nymd,10000) / 100
      nd   = mod(nymd,100)
      !Allow override for NoLeap simulations
      IF (trim(caltype) .EQ. 'standard' ) THEN
        leap = mod(ny,400).EQ.0 .OR.                           &
             ( mod(ny,4).EQ.0 .AND. mod(ny,100).NE.0 )
      ELSE
        leap=.false.
      ENDIF
      !
      ! Loop over months :
      !
      IF (nm.GT.2 .AND. leap)  nd = nd + 1
      !
40    CONTINUE
      IF (nm.LE.1)  GO TO 60
      nm = nm - 1
      nd = nd + ndpm(nm)
      GO TO 40
      !
60    CONTINUE
      mymd21 = nd
      !
      RETURN
      !/
      !/ End of MYMD21 ----------------------------------------------------- /
      !/
    END FUNCTION mymd21
    !/
    !/ End of DSEC21 ----------------------------------------------------- /
    !/
  END FUNCTION dsec21
  !/ ------------------------------------------------------------------- /
  REAL function tdiff ( t1, t2 )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           Arun Chawla             |
    !/                  |           Mark Szyszka            |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         02-Feb-2014 |
    !/                  +-----------------------------------+
    !/
    !/    02-Feb-2014 : Original code         ( version 4.18 )
    !/
    !/
    !  1. Purpose :
    !
    !     Calculate the time difference in seconds between two time arrays
    !     that have been generated from the F90 internal function
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       Tn      I.A.   I   This is an integer array returned from the
    !                          internal subroutine DATE_AND_TIME. The type
    !                          is integer(8). Individual values are
    !                          Tn(1)    the year
    !                          Tn(2)    the month
    !                          Tn(3)    day of the month
    !                          Tn(4)    time difference with UTC in minutes
    !                          Tn(5)    hour of the day
    !                          Tn(6)    minutes of the hour
    !                          Tn(7)    seconds of the minute
    !                          Tn(8)    milli seconds of the second
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any routine.
    !
    !  7. Remarks :
    !
    !     This code has been provided by Mark Szyszka of RPSGROUP
    !
    !  8. Structure :
    !
    !     See source code.
    !
    !  9. Switches :
    !
    !     !/S  Enable subroutine tracing using STRACE.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(IN)     :: t1(8), t2(8)
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: a1, b1, c1, d1, a2, b2, c2, d2
    REAL                    :: e1, e2
#ifdef W3_S
    INTEGER, SAVE           :: ient = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'TDIFF')
#endif
    !
    ! Convert dates and times :
    !
    a1 = (14-t1(2))/12
    b1 = t1(1) + 4800 - a1
    c1 = t1(2) + 12*a1 - 3
    d1 = t1(3) + (153*c1 + 2)/5 + 365*b1 + b1/4 -b1/100 + b1/400
    e1 = 3600.0*t1(5) + 60.0*(t1(6)-t1(4)) + t1(7) + t1(8)/1000.0
    !
    a2 = (14-t2(2))/12
    b2 = t2(1) + 4800 - a2
    c2 = t2(2) + 12*a2 - 3
    d2 = t2(3) + (153*c2 + 2)/5 + 365*b2 + b2/4 -b2/100 + b2/400
    e2 = 3600.0*t2(5) + 60.0*(t2(6)-t2(4)) + t2(7) + t2(8)/1000.0
    !
    tdiff = 86400.0*(d2-d1) + e2-e1
    !
    RETURN
    !/
    !/ End of TDIFF ------------------------------------------------------ /
    !/
  END FUNCTION tdiff
  !/ ------------------------------------------------------------------- /
  SUBROUTINE stme21 ( TIME , DTME21 )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           H. L. Tolman            |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         23-Nov-1999 |
    !/                  +-----------------------------------+
    !/
    !/    21-Jun-1993 : Final FORTRAN 77                    ( version 1.18 )
    !/    23-Nov-1999 : Upgrade to FORTRAN 90               ( version 2.00 )
    !/
    !  1. Purpose :
    !
    !     Converts time to more readable string.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       TIME    I.A.  I   Time in YYYYMMDD HHMMSS format.
    !                         TIME(1) < 0 indicates that time is not set.
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !       None.
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(IN)     :: TIME(2)
    CHARACTER, INTENT(OUT)  :: DTME21*23
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: IY, IMO, ID, IH, IMI, IS
    !/
    !/ ------------------------------------------------------------------- /
    !/
    IF ( time(1) .LT. 0 ) THEN
      dtme21 = ' date and time not set.'
    ELSE
      iy     = time(1) / 10000
      imo    = mod(time(1),10000) / 100
      id     = mod(time(1),100)
      ih     = time(2) / 10000
      imi    = mod(time(2),10000) / 100
      is     = mod(time(2),100)
      WRITE (dtme21,900) iy, imo, id, ih, imi, is
    ENDIF
    !
    RETURN
    !
    ! Formats
    !
900 FORMAT (i4.4,'/',i2.2,'/',i2.2,' ',i2.2,':',i2.2,':',i2.2,' UTC')
    !/
    !/ End of STME21 ----------------------------------------------------- /
    !/
  END SUBROUTINE stme21
 
  !/ ------------------------------------------------------------------- /
  INTEGER FUNCTION julday(id,mm,iyyy)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           F. Ardhuin              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         23-Sep-2012 |
    !/                  +-----------------------------------+
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    INTEGER(KIND=4),    INTENT(in)  :: id,mm,iyyy
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER(KIND=4), PARAMETER :: igreg=15+31*(10+12*1582)
    INTEGER(KIND=4) ja,jm,jy
    jy=iyyy
    IF (jy.EQ.0) WRITE(6,*) 'There is no zero year !!'
    IF (jy.LT.0) jy=jy+1
    IF (mm.GT.2) THEN
      jm=mm+1
    ELSE
      jy=jy-1
      jm=mm+13
    ENDIF
    julday=int(365.25*jy)+int(30.6001*jm)+id+1720995
    IF (id+31*(mm+12*iyyy).GE.igreg) THEN
      ja=int(0.01*jy)
      julday=julday+2-ja+int(0.25*ja)
    END IF
    RETURN
    !/
    !/ End of JULDAY ----------------------------------------------------- /
    !/
  END FUNCTION julday
 
  !/ ------------------------------------------------------------------- /
  SUBROUTINE caldat(julian,id,mm,iyyy)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           F. Ardhuin              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         23-Sep-2012 |
    !/                  +-----------------------------------+
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    ! See numerical recipes 2nd ed. The order of month and day have been swapped!
    !
    !/
    INTEGER(KIND=4),    INTENT(in)  :: julian
    INTEGER(KIND=4),    INTENT(out) :: id,mm,iyyy
    INTEGER(KIND=4), PARAMETER :: IGREG=2299161
    INTEGER(KIND=4) ja,jalpha,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
    END IF
    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)
    id=jb-jd-int(30.6001*je)
    mm=je-1
    IF (mm.GT.12) mm=mm-12
    iyyy=jc-4715
    IF (mm.GT.2) iyyy=iyyy-1
    IF (iyyy.LE.0) iyyy=iyyy-1
    RETURN
    !/
    !/ End of CALDAT ----------------------------------------------------- /
    !/
  END SUBROUTINE caldat
  !/ ------------------------------------------------------------------- /
  REAL(KIND=8) function  time2hours(time)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           F. Ardhuin              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         26-Sep-2012 |
    !/                  +-----------------------------------+
    !
    !  1. Purpose :
    !
    !     Gives date as real number
    !
    !  2. Method :
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       TIME    I.A.  I/O  (1) Current date in YYYYMMDD format.
    !                          (2) Current time in HHMMSS format.
    !       DTIME   Real   I   Time step in seconds.
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !      IYMD21    Func. Internal Increment date in YYYYMMDD format.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any other routine.
    !
    !  8. Structure :
    !
    !     See source code.
    !
    !  9. Switches :
    !
    !     !/S  Enable subroutine tracing using STRACE.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(INOUT)  :: time(2)
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: iy,imo,id,ih,imi,is
    INTEGER(KIND=4)         :: jday
#ifdef W3_S
    INTEGER, SAVE           :: ient = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'TICK21')
#endif
    !
    ! Zero increment: get "legal" date
    !
    iy     = time(1) / 10000
    imo    = mod(time(1),10000) / 100
    id     = mod(time(1),100)
    ih     = time(2) / 10000
    imi    = mod(time(2),10000) / 100
    is     = mod(time(2),100)
    jday    = julday(id,imo,iy)
    time2hours = 24.d0*dfloat(jday)+dfloat(ih)+dfloat(is+imi*60)/3600.d0
    RETURN
    !/
    !/ End of TIME2HOURS-------------------------------------------------- /
    !/
  END FUNCTION time2hours
  !/ ------------------------------------------------------------------- /
  SUBROUTINE prinit
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           H. L. Tolman            |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         06-May-2005 !
    !/                  +-----------------------------------+
    !/
    !/    06-May-2005 : Origination.                        ( version 3.07 )
    !/
    !  1. Purpose :
    !
    !     Initialize profiling routine PRTIME.
    !
    !  2. Method :
    !
    !     FORTRAN 90 SYSTEM_CLOCK intrinsic routine.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      SYSTEM_CLOCK
    !                Sur.    n/a    Get system time
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !  6. Error messages :
    !
    !  7. Remarks :
    !
    !  8. Structure :
    !
    !  9. Switches :
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    IMPLICIT NONE
    !/
    ! -------------------------------------------------------------------- /
    !
    CALL date_and_time ( values=prftb )
    !
    flprof = .true.
    !
    RETURN
    !/
    !/ End of PRINIT ----------------------------------------------------- /
    !/
  END SUBROUTINE prinit
  !/ ------------------------------------------------------------------- /
  SUBROUTINE prtime ( PTIME )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           H. L. Tolman            |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         06-May-2005 !
    !/                  +-----------------------------------+
    !/
    !/    06-May-2005 : Origination.                        ( version 3.07 )
    !/
    !  1. Purpose :
    !
    !     Get wallclock time for profiling purposes.
    !
    !  2. Method :
    !
    !     FORTRAN 90 SYSTEM_CLOCK intrinsic routine.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       PTIME   Real   O   Time retrieced from system.
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      SYSTEM_CLOCK
    !                Sur.    n/a    Get system time
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any, after PRINIT has been called.
    !
    !  6. Error messages :
    !
    !     - If no initialization, returned time equals -1.
    !     - If no system clock, returned time equals -1.
    !
    !  7. Remarks :
    !
    !  8. Structure :
    !
    !  9. Switches :
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    REAL, INTENT(OUT)       :: PTIME
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: PRFTA(8)
    !
    ! -------------------------------------------------------------------- /
    !
    ptime  = -1.
    !
    IF ( .NOT. flprof ) RETURN
    !
    CALL date_and_time ( values=prfta )
    ptime  = tdiff( prftb,prfta )
    !
    RETURN
    !/
    !/ End of PRTIME ----------------------------------------------------- /
    !/
  END SUBROUTINE prtime
 
  !/ ------------------------------------------------------------------- /
 
  SUBROUTINE t2d(TIME,DAT,IERR)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         04-Jan-2018 |
    !/                  +-----------------------------------+
    !/
    !/    04-Jan-2018 : Origination                         ( version 6.04 )
    !/
    !  1. Purpose :
    !
    !     Converts time array from TIME(2) to DAT(8)
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       TIME     I.A.     I   Time array like 'YYYYMMDD HHMMSS'
    !       DAT      I.A.     O   Time array like returned by DATE_AND_TIME(3f)
    !       IERR     Integer  O   Error code returned
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER,INTENT(IN)            :: TIME(2)  ! array like 'YYYYMMDD HHMMSS'
    INTEGER,INTENT(OUT)           :: DAT(8)   ! array like returned by DATE_AND_TIME(3f)
    INTEGER,INTENT(OUT)           :: IERR     ! Error return, 0 for successful execution
    ! Otherwise return 1
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'T2D')
#endif
    !
    dat(1)=time(1)/10000
    dat(2)=(time(1)-dat(1)*10000)/100
    dat(3)=time(1)-dat(1)*10000-100*dat(2)
    dat(4)=0
    dat(5)=time(2)/10000
    dat(6)=(time(2)-dat(5)*10000)/100
    dat(7)=time(2)-dat(5)*10000-100*dat(6)
    dat(8)=0
    ierr=0
    !
    RETURN
    !/
    !/ End of T2D ----------------------------------------------------- /
    !/
  END SUBROUTINE t2d
 
  !/ ------------------------------------------------------------------- /
 
 
  SUBROUTINE d2t(DAT,TIME,IERR)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         04-Jan-2018 |
    !/                  +-----------------------------------+
    !/
    !/    04-Jan-2018 : Origination                         ( version 6.04 )
    !/
    !  1. Purpose :
    !
    !     Converts time array from DAT(8) to TIME(2)
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       DAT      I.A.     I   Time array like returned by DATE_AND_TIME(3f)
    !       TIME     I.A.     O   Time array like 'YYYYMMDD HHMMSS'
    !       IERR     Integer  O   Error code returned
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER,INTENT(IN)            :: DAT(8)   ! array like returned by DATE_AND_TIME(3f)
    INTEGER,INTENT(OUT)           :: TIME(2)  ! array like 'YYYYMMDD HHMMSS'
    INTEGER,INTENT(OUT)           :: IERR     ! Error return, 0 for successful execution
    ! Otherwise return 1
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'D2T')
#endif
    !
    time(1)=dat(1)*10000+dat(2)*100+dat(3)
    time(2)=dat(5)*10000+dat(6)*100+dat(7)
    ierr=0
    !
    RETURN
    !/
    !/ End of D2T ----------------------------------------------------- /
    !/
  END SUBROUTINE d2t
 
  !/ ------------------------------------------------------------------- /
 
  SUBROUTINE d2j(DAT,JULIAN,IERR)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         04-Jan-2018 |
    !/                  +-----------------------------------+
    !/
    !/    04-Jan-2018 : Origination from m_time library     ( version 6.04 )
    !/    23-Feb-2024 : Updated to handle 360_day calendar  ( version 7.14 )
    !/
    !  1. Purpose :
    !
    !     Converts proleptic Gregorian date array to Julian Day
    !
    !
    ! * UDUNITS standard : mixed Gregorian/Julian  calendar  system.
    !                      Dates  prior to 1582-10-15 are assumed to use
    !                      the Julian calendar, which was introduced by Julius Caesar
    !                      in 46 BCE and is based on a year that is exactly 365.25 days
    !                      long.  Dates on and after 1582-10-15 are assumed to use  the
    !                      Gregorian calendar, which was introduced on that date and is
    !                      based on a year that is exactly 365.2425 days long.  (A year
    !                      is  actually  approximately 365.242198781 days long.)
    !
    ! * There is no year zero
    ! * Julian Day must be non-negative
    ! * Julian Day starts at noon; while Civil Calendar date starts at midnight
    ! * If CALTYPE is "360_day" a simpler calculation is used (30 days in every
    !   month) with a reference date of 1800-01-01.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       DAT      I.A.     I   Time array like returned by DATE_AND_TIME(3f)
    !       JULIAN   Double   O   Julian day
    !       IERR     Integer  O   Error code returned
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER,INTENT(IN)            :: DAT(8)   ! array like returned by DATE_AND_TIME(3f)
    DOUBLE PRECISION,INTENT(OUT)  :: JULIAN   ! Julian Day (non-negative, but may be non-integer)
    INTEGER,INTENT(OUT)           :: IERR     ! Error return, 0 for successful execution
    ! -1=invalid year,-2=invalid month,-3=invalid day,
    ! -4=invalid date (29th Feb, non leap-year)
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: YEAR, MONTH, DAY, UTC, HOUR, MINUTE
    REAL                    :: SECOND
    INTEGER                 :: A, Y, M, JDN
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'D2J')
#endif
    !
    year   = dat(1)                        ! Year
    month  = dat(2)                        ! Month
    day    = dat(3)                        ! Day
    utc    = dat(4)*60                     ! Delta from UTC, convert from minutes to seconds
    hour   = dat(5)                        ! Hour
    minute = dat(6)                        ! Minute
    second = dat(7)-utc+dat(8)/1000.d0     ! Second   ! correction for time zone and milliseconds
 
    julian = -huge(99999)                  ! this is the date if an error occurs and IERR is < 0
 
    ! Special case for 360 day climate calendar; return a pseudo-Julian day
    ! Assumes a reference date of 1800-01-01 00:00:00
    IF( caltype .EQ. "360_day" ) THEN
      julian = (year - 1800) * 360.0 +     &  ! Years since 1800
            (month - 1) * 30.0  +          &  
            (day - 1) +                    & 
            hour / 24.0_8 +                &
            minute / 1440.0_8 +            &
            second / 86400.0_8
 
      ierr = 0
      RETURN
    ENDIF
 
    ! Standard/Gregorian calendar - return standard Julian day calculation:
    IF(year==0 .or. year .lt. -4713) THEN
      ierr=-1
      RETURN
    END IF
 
    !  You must compute first the number of years (Y) and months (M) since March 1st -4800 (March 1, 4801 BC)
    a=(14-month)/12 ! A will be 1 for January or Febuary, and 0 for other months, with integer truncation
    y=year+4800-a
    m=month+12*a-3  ! M will be 0 for March and 11 for Febuary
 
    !  All years in the BC era must be converted to astronomical years, so that 1BC is year 0, 2 BC is year "-1", etc.
    !  Convert to a negative number, then increment towards zero
    !  Starting from a Gregorian calendar date
    jdn=day + (153*m+2)/5 + 365*y + y/4 - y/100 + y/400 - 32045  !  with integer truncation
 
    !  Finding the Julian date given the JDN (Julian day number) and time of day
    julian=dble(jdn) + dble(hour-12)/24.0d0 + dble(minute)/1440.0d0 + dble(second)/86400.0d0
 
    ! Check if Julian Day is non-negative
    IF(julian.lt.0.d0) THEN
      ierr=1
    ELSE
      ierr=0
    END IF
    !
    RETURN
    !/
    !/ End of D2J ----------------------------------------------------- /
    !/
  END SUBROUTINE d2j
 
  !/ ------------------------------------------------------------------- /
 
  SUBROUTINE j2d(JULIAN,DAT,IERR)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         04-Jan-2018 |
    !/                  +-----------------------------------+
    !/
    !/    04-Jan-2018 : Origination from m_time library     ( version 6.04 )
    !/    23-Feb-2024 : Upated to handle 360_day calendar   ( version 7.14 )
    !/
    !  1. Purpose :
    !
    !     Converts Julian Day to date array
    !
    ! * There is no year zero
    ! * Julian Day must be non-negative
    ! * Julian Day starts at noon; while Civil Calendar date starts at midnight
    ! * If CALTYPE is "360_day" a simpler calculation is used (30 days in every
    !   month) with a reference date of 1800-01-01.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       JULIAN   Double   I   Julian day
    !       DAT      I.A.     O   Time array like returned by DATE_AND_TIME(3f)
    !       IERR     Integer  O   Error code returned
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    DOUBLE PRECISION,INTENT(IN)   :: JULIAN   ! Julian Day (non-negative, but may be non-integer)
    INTEGER,INTENT(OUT)           :: DAT(8)   ! array like returned by DATE_AND_TIME(3f)
    INTEGER,INTENT(OUT)           :: IERR     ! Error return, 0 for successful execution
    !                                         ! otherwise return 1
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    REAL                      :: SECDAY=86400.0d0
    INTEGER                   :: TIMEZONE(8), TZ
 
    REAL                      :: SECOND
    INTEGER                   :: YEAR, MONTH, DAY, HOUR, MINUTE
    INTEGER                   :: JALPHA,JA,JB,JC,JD,JE,IJUL
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'J2D')
#endif
 
    !
    IF(caltype .EQ. 'standard' .AND. julian .LT. 0.d0) THEN 
      ! Negative Julian Day not allowed
      ierr=1
      RETURN
    END IF
 
    !CALL DATE_AND_TIME(values=TIMEZONE)         ! Get the timezone
    !TZ=TIMEZONE(4)
    tz=0                                         ! Force to UTC timezone
 
    ! Calculation for time (hour,min,sec) same for Julian
    ! and 360_day calendars:
    ijul=idint(julian)                           ! Integral Julian Day
    second=sngl((julian-dble(ijul))*secday)      ! Seconds from beginning of Jul. Day
    second=second+(tz*60)
 
    IF(caltype .EQ. "standard") THEN
      IF(second.GE.(secday/2.0d0)) THEN          ! In next calendar day
        ijul=ijul+1
        second=second-(secday/2.0d0)             ! Adjust from noon to midnight
      ELSE                                       ! In same calendar day
        second=second+(secday/2.0d0)             ! Adjust from noon to midnight
      END IF
    END IF
 
    IF(second.GE.secday) THEN                    ! Final check to prevent time 24:00:00
      ijul=ijul+1
      second=second-secday
    END IF
 
    minute=int(second/60.0)                      ! Integral minutes from beginning of day
    second=second-float(minute*60)               ! Seconds from beginning of minute
    hour=minute/60                               ! Integral hours from beginning of day
    minute=minute-hour*60                        ! Integral minutes from beginning of hour
 
    IF(caltype .EQ. '360_day') THEN
      ! Calculate date parts for 360 day climate calendar
      year = int(julian / 360) + 1800 ! (base year is 1800)
      month = mod(int(julian / 30), 12) + 1
      day = mod(int(julian), 30) + 1
    ELSE ! Stardard Julian day calculation
      !---------------------------------------------
      jalpha=idint((dble(ijul-1867216)-0.25d0)/36524.25d0) ! Correction for Gregorian Calendar
      ja=ijul+1+jalpha-idint(0.25d0*dble(jalpha))
      !---------------------------------------------
 
      jb=ja+1524
      jc=idint(6680.d0+(dble(jb-2439870)-122.1d0)/365.25d0)
      jd=365*jc+idint(0.25d0*dble(jc))
      je=idint(dble(jb-jd)/30.6001d0)
      day=jb-jd-idint(30.6001d0*dble(je))
      month=je-1
 
      IF(month.GT.12) THEN
        month=month-12
      END IF
 
      year=jc-4715
      IF(month.GT.2) THEN
        year=year-1
      END IF
  
      IF(year.LE.0) THEN
        year=year-1
      END IF
    ENDIF
  
    dat(1)=year
    dat(2)=month
    dat(3)=day
    dat(4)=tz
    dat(5)=hour
    dat(6)=minute
    dat(7)=int(second)
    dat(8)=int((second-int(second))*1000.0)
    ierr=0
    !
    RETURN
    !/
    !/
  END SUBROUTINE j2d
 
  !/ ------------------------------------------------------------------- /
  DOUBLE PRECISION FUNCTION tsub ( T1, T2 )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         18-Jun-2020 |
    !/                  +-----------------------------------+
    !/
    !/    15-May-2018 : Origination                         ( version 6.05 )
    !/    18-Jun-2020 : Addition of 360-day calendar        ( version 7.08 )
    !/
    !  1. Purpose :
    !
    !     Substract two time arrays to get the time difference in days
    !     in a way to avoid decimal approximation error
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       T1       I.A.     I   Time array
    !       T2       I.A.     I   Time array
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any routine.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(IN)     :: t1(8), t2(8)
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER                 :: a1, b1, c1, d1, a2, b2, c2, d2
    DOUBLE PRECISION        :: e1, e2
#ifdef W3_S
    INTEGER, SAVE           :: ient = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'TSUB')
#endif
    !
    ! Convert dates and times :
    !
    IF (trim(caltype) .EQ. '360_day' ) THEN
      a1 = (t2(1)-t1(1))*360 + (t2(2)-t1(2))*30 + (t2(3)-t1(3))
 
      e1 = 3600.0*t1(5) + 60.0*(t1(6)-t1(4)) + t1(7) + t1(8)/1000.0
      e2 = 3600.0*t2(5) + 60.0*(t2(6)-t2(4)) + t2(7) + t2(8)/1000.0
      !
      tsub = dble(a1) + (e2-e1)/86400.0d0
    ELSE
      a1 = (14-t1(2))/12
      b1 = t1(1) + 4800 - a1
      c1 = t1(2) + 12*a1 - 3
      d1 = t1(3) + (153*c1 + 2)/5 + 365*b1
      IF (trim(caltype) .EQ. 'standard' ) THEN
        d1 = d1 + b1/4 -b1/100 + b1/400
      ENDIF
      e1 = 3600.0*t1(5) + 60.0*(t1(6)-t1(4)) + t1(7) + t1(8)/1000.0
      !
      a2 = (14-t2(2))/12
      b2 = t2(1) + 4800 - a2
      c2 = t2(2) + 12*a2 - 3
      d2 = t2(3) + (153*c2 + 2)/5 + 365*b2
      IF (trim(caltype) .EQ. 'standard' ) THEN
        d2 = d2 + b2/4 -b2/100 + b2/400
      ENDIF
      e2 = 3600.0*t2(5) + 60.0*(t2(6)-t2(4)) + t2(7) + t2(8)/1000.0
      !
      tsub = dble(d2-d1) + (e2-e1)/86400.0d0
    ENDIF
    !
    RETURN
    !/
    !/ End of TSUB ------------------------------------------------------- /
    !/
  END FUNCTION tsub
 
  !/ ------------------------------------------------------------------- /
  DOUBLE PRECISION FUNCTION tsubsec ( T1, T2 )
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |           C. Bunney               |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         18-Jun-2020 |
    !/                  +-----------------------------------+
    !/
    !/    15-May-2018 : Origination (adapted from TSUB)     ( version 7.12 )
    !/
    !  1. Purpose :
    !
    !     Substract two time arrays to get the time difference in seconds.
    !     The milliseconds part of the array (index 8) is rounded to the
    !     nearest whole second.
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       T1       I.A.     I   Time array
    !       T2       I.A.     I   Time array
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !     Any routine.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER, INTENT(IN)     :: t1(8), t2(8)
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
    INTEGER(KIND=8)         :: a1, b1, c1, d1, a2, b2, c2, d2
    INTEGER(KIND=8)         :: e1, e2
#ifdef W3_S
    INTEGER, SAVE           :: ient = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'TSUBSEC')
#endif
    !
    IF (trim(caltype) .EQ. '360_day' ) THEN
      a1 = (t2(1)-t1(1))*360 + (t2(2)-t1(2))*30 + (t2(3)-t1(3))
 
      e1 = 3600.0*t1(5) + 60.0*(t1(6)-t1(4)) + t1(7) + nint(t1(8) / 1000.0)
      e2 = 3600.0*t2(5) + 60.0*(t2(6)-t2(4)) + t2(7) + nint(t2(8) / 1000.0)
      !
      tsubsec = a1 * 86400 + (e2-e1)
    ELSE
      a1 = (14-t1(2))/12
      b1 = t1(1) + 4800 - a1
      c1 = t1(2) + 12*a1 - 3
      d1 = t1(3) + (153*c1 + 2)/5 + 365*b1
      IF (trim(caltype) .EQ. 'standard' ) THEN
        d1 = d1 + b1/4 -b1/100 + b1/400
      ENDIF
      e1 = 3600.0*t1(5) + 60.0*(t1(6)-t1(4)) + t1(7) + nint(t1(8) / 1000.0)
      !
      a2 = (14-t2(2))/12
      b2 = t2(1) + 4800 - a2
      c2 = t2(2) + 12*a2 - 3
      d2 = t2(3) + (153*c2 + 2)/5 + 365*b2
      IF (trim(caltype) .EQ. 'standard' ) THEN
        d2 = d2 + b2/4 -b2/100 + b2/400
      ENDIF
      e2 = 3600.0*t2(5) + 60.0*(t2(6)-t2(4)) + t2(7) + nint(t1(8) / 1000.0)
      !
      tsubsec = (d2-d1)*86400 + (e2-e1)
    ENDIF
    !
    RETURN
    !/
    !/ End of TSUBSEC ---------------------------------------------------- /
    !/
  END FUNCTION tsubsec
 
 
  !/ ------------------------------------------------------------------- /
 
  SUBROUTINE u2d(UNITS,DAT,IERR)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           M. Accensi              |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         15-May-2018 |
    !/                  +-----------------------------------+
    !/
    !/    15-May-2018 : Origination                         ( version 6.05 )
    !/
    !  1. Purpose :
    !
    !     Convert time units attribute to date array
    !
    ! * units attribute must respect convention ISO8601
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       UNITS    Char     I   Units attribute
    !       DAT      I.A.     O   Time array like returned by DATE_AND_TIME(3f)
    !       IERR     Integer  O   Error code returned
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    USE w3servmd, ONLY: extcde
    USE w3odatmd, ONLY: ndse
    !
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    CHARACTER(*),INTENT(IN)       :: UNITS    ! Units attribute
    INTEGER,INTENT(OUT)           :: DAT(8)   ! array like returned by DATE_AND_TIME(3f)
    INTEGER,INTENT(OUT)           :: IERR     ! Error return, 0 for successful execution
    ! Otherwise returnb 1
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'U2D')
#endif
    !
 
    dat(4) = 0  ! force to UTC timezone
    dat(8) = 0  ! force milliseconds to 0
 
 
    ! seconds
    IF (index(units, "seconds").NE.0) THEN
      ! seconds since YYYY-MM-DD hh:mm:ss
      IF (index(units, "-", .true.).EQ.22) THEN
        READ(units(15:18),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(20:21),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(23:24),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        READ(units(26:27),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
        READ(units(29:30),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
        READ(units(32:33),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ! seconds since YYYY-M-D ...
      ELSE IF (index(units, "-", .true.).EQ.21) THEN
        READ(units(15:18),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(20:20),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(22:22),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        ! seconds since YYYY-M-D h:m:s
        IF (index(units, ":", .false.).EQ.25) THEN
          READ(units(24:24),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(26:26),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(28:28),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
          ! seconds since YYYY-M-D hh:mm:ss
        ELSE IF (index(units, ":", .false.).EQ.26) THEN
          READ(units(24:25),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(27:28),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(30:31),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ELSE
          GOTO 804
        END IF
      ELSE
        GOTO 804
      END IF
 
      ! days
    ELSE IF (index(units, "days").NE.0) THEN
      ! days since YYYY-MM-DD hh:mm:ss
      IF (index(units, "-", .true.).EQ.19) THEN
        READ(units(12:15),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(17:18),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(20:21),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        READ(units(23:24),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
        READ(units(26:27),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
        READ(units(29:30),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ! days since YYYY-M-D ...
      ELSE IF (index(units, "-", .true.).EQ.18) THEN
        READ(units(12:15),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(17:17),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(19:19),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        ! days since YYYY-M-D h:m:s
        IF (index(units, ":", .false.).EQ.22) THEN
          READ(units(21:21),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(23:23),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(25:25),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
          ! days since YYYY-M-D hh:mm:ss
        ELSE IF (index(units, ":", .false.).EQ.23) THEN
          READ(units(21:22),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(24:25),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(27:28),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ELSE
          GOTO 804
        END IF
      ELSE
        GOTO 804
      END IF
 
      ! hours
    ELSE IF (index(units, "hours").NE.0) THEN
      ! hours since YYYY-MM-DD hh:mm:ss
      IF (index(units, "-", .true.).EQ.20) THEN
        READ(units(13:16),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(18:19),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(21:22),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        READ(units(24:25),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
        READ(units(27:28),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
        READ(units(30:31),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ! hours since YYYY-M-D ...
      ELSE IF (index(units, "-", .true.).EQ.19) THEN
        READ(units(13:16),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(18:18),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(20:20),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        ! hours since YYYY-M-D h:m:s
        IF (index(units, ":", .false.).EQ.23) THEN
          READ(units(22:22),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(24:24),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(26:26),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
          ! hours since YYYY-M-D hh:mm:ss
        ELSE IF (index(units, ":", .false.).EQ.24) THEN
          READ(units(22:23),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(25:26),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(28:29),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ELSE
          GOTO 804
        END IF
      ELSE
        GOTO 804
      END IF
 
      ! minutes
    ELSE IF (index(units, "minutes").NE.0) THEN
      ! minutes since YYYY-MM-DD hh:mm:ss
      IF (index(units, "-", .true.).EQ.22) THEN
        READ(units(15:18),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(20:21),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(23:24),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        READ(units(26:27),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
        READ(units(29:30),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
        READ(units(32:33),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ! minutes since YYYY-M-D ...
      ELSE IF (index(units, "-", .true.).EQ.21) THEN
        READ(units(15:18),'(I4.4)',END=804,ERR=805,IOSTAT=IERR) DAT(1)
        READ(units(20:20),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(2)
        READ(units(22:22),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(3)
        ! minutes since YYYY-M-D h:m:s
        IF (index(units, ":", .false.).EQ.25) THEN
          READ(units(24:24),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(26:26),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(28:28),'(I1.1)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
          ! minutes since YYYY-M-D hh:mm:ss
        ELSE IF (index(units, ":", .false.).EQ.26) THEN
          READ(units(24:25),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(5)
          READ(units(27:28),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(6)
          READ(units(30:31),'(I2.2)',END=804,ERR=805,IOSTAT=IERR) DAT(7)
        ELSE
          GOTO 804
        END IF
      ELSE
        GOTO 804
      END IF
 
      ! nothing
    ELSE
      GOTO 804
    END IF
    !
    GOTO 888
    !
    ! Error escape locations
    !
804 CONTINUE
    WRITE (ndse,1004) trim(units)
    CALL extcde ( 44 )
    !
805 CONTINUE
    WRITE (ndse,1005) ierr
    CALL extcde ( 45 )
    !
888 CONTINUE
 
    !
    ! Formats
    !
1004 FORMAT (/' *** WAVEWATCH III ERROR IN W3TIMEMD : '/               &
         '     PREMATURE END OF TIME ATTRIBUTE '/                 &
         '     ',a/                                               &
         '     DIFFERS FROM CONVENTIONS ISO8601 '/                &
         '     XXX since YYYY-MM-DD hh:mm:ss'/                    &
         '     XXX since YYYY-M-D h:m:s'/                         &
         '     XXX since YYYY-M-D hh:mm:ss'/)
    !
1005 FORMAT (/' *** WAVEWATCH III ERROR IN W3TIMEMD : '/               &
         '     ERROR IN READING OF TIME ATTRIBUTE '/              &
         '     ',a/                                               &
         '     DIFFERS FROM CONVENTIONS ISO8601 '/                &
         '     XXX since YYYY-MM-DD hh:mm:ss'/                    &
         '     XXX since YYYY-M-D h:m:s'/                         &
         '     XXX since YYYY-M-D hh:mm:ss'/                      &
         '     IOSTAT =',i5/)
    !
    RETURN
    !/
    !/ End of U2D ----------------------------------------------------- /
    !/
  END SUBROUTINE u2d
 
 
  !/ ------------------------------------------------------------------- /
 
  !/ ------------------------------------------------------------------- /
 
  SUBROUTINE t2iso(TIME,ISODT)
    !/
    !/                  +-----------------------------------+
    !/                  | WAVEWATCH III           NOAA/NCEP |
    !/                  |           C. Bunney               |
    !/                  |                        FORTRAN 90 |
    !/                  | Last update :         19-Jan-2020 |
    !/                  +-----------------------------------+
    !/
    !/    19-Jan-2020 : Origination                         ( version 7.12 )
    !/
    !  1. Purpose :
    !
    !     Convert time array to ISO8601 format string
    !
    !  3. Parameters :
    !
    !     Parameter list
    !     ----------------------------------------------------------------
    !       TIME     I.A.     I   Time array like 'YYYYMMDD HHMMSS'
    !       ISODT    Char.    O   ISO8601 datetime string
    !     ----------------------------------------------------------------
    !
    !  4. Subroutines used :
    !
    !      Name      Type  Module   Description
    !     ----------------------------------------------------------------
    !      STRACE    Subr. W3SERVMD Subroutine tracing.
    !     ----------------------------------------------------------------
    !
    !  5. Called by :
    !
    !       Any subroutine/program.
    !
    ! 10. Source code :
    !
    !/ ------------------------------------------------------------------- /
    !/
    USE w3servmd, ONLY: extcde
    USE w3odatmd, ONLY: ndse
    !
    IMPLICIT NONE
    !/
    !/ ------------------------------------------------------------------- /
    !/ Parameter list
    !/
    INTEGER,INTENT(IN)            :: TIME(2)  ! array like 'YYYYMMDD HHMMSS'
    CHARACTER(LEN=32),INTENT(OUT) :: ISODT    ! ISO date time
    !/
    !/ ------------------------------------------------------------------- /
    !/ Local parameters
    !/
#ifdef W3_S
    INTEGER, SAVE           :: IENT = 0
#endif
    !/
    !/ ------------------------------------------------------------------- /
    !/
#ifdef W3_S
    CALL strace (ient, 'T2ISO')
#endif
    !
    !/
    WRITE(isodt,'(I4,"-",I2.2,"-",I2.2,"T",I2.2,":",I2.2,":",I2.2)') &
         time(1) / 10000,                                              &
         mod(time(1) / 100, 100),                                      &
         mod(time(1), 100),                                            &
         time(2) / 10000,                                              &
         mod(time(2) / 100, 100),                                      &
         mod(time(2), 100)
    !/
    !/ End of T2ISO ------------------------------------------------------ /
    !/
  END SUBROUTINE t2iso
 
  !/ End of module W3TIMEMD -------------------------------------------- /
  !/
END MODULE w3timemd