mode_datetime.f90

!MNH_LIC Copyright 2018 CNRS, Meteo-France and Universite Paul Sabatier
!MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
!MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
!MNH_LIC for details. version 1.
!-----------------------------------------------------------------
MODULE MODE_DATETIME
!
USE MODD_TYPE_DATE
!
USE MODE_MSG
!
IMPLICIT NONE
!
PRIVATE
!
PUBLIC :: DATETIME_DISTANCE, DATETIME_CORRECTDATE
PUBLIC :: OPERATOR(<)
PUBLIC :: OPERATOR(>=)
!
!Reference date (do not change it)
!To work with DATETIME_TIME2REFERENCE, we assume the year is a multiple of 400 + 1 and the date is January 1st (and time=0.)
TYPE(DATE_TIME),PARAMETER :: TPREFERENCE_DATE = DATE_TIME( TDATE=DATE(1601,1,1), TIME=0. )
!
INTERFACE OPERATOR(<)
  MODULE PROCEDURE DATETIME_LT
END INTERFACE
!
INTERFACE OPERATOR(>=)
  MODULE PROCEDURE DATETIME_GE
END INTERFACE
!
CONTAINS
!
SUBROUTINE DATETIME_TIME2REFERENCE(TPDATE,PDIST)
!
!Compute number of seconds since reference date (and time)
!
TYPE(DATE_TIME), INTENT(IN)  :: TPDATE
REAL,            INTENT(OUT) :: PDIST
!
INTEGER(KIND=8) :: ILEAPS                          !Number of leap days
INTEGER(KIND=8) :: IDAYS                           !Number of days since reference date
INTEGER(KIND=8) :: IYEARS                          !Number of years since reference date
INTEGER(KIND=8) :: IDAY_CUR, IMONTH_CUR, IYEAR_CUR !Currrent day, month and year
REAL            :: ZSEC                            !Current time of the day (in seconds)
TYPE(DATE_TIME) :: TZDATE
!
ILEAPS = 0
IDAYS  = 0
!
TZDATE = TPDATE
CALL DATETIME_CORRECTDATE(TZDATE)
!
IYEAR_CUR  = TZDATE%TDATE%YEAR
IMONTH_CUR = TZDATE%TDATE%MONTH
IDAY_CUR   = TZDATE%TDATE%DAY
ZSEC = TZDATE%TIME
!
!Compute number of days since beginning of the year
IF ( ((MOD(IYEAR_CUR,4)==0).AND.(MOD(IYEAR_CUR,100)/=0)) .OR. (MOD(IYEAR_CUR,400)==0)) ILEAPS=1
SELECT CASE(IMONTH_CUR)
  CASE(1)
    IDAYS = IDAY_CUR-1
  CASE(2)
    IDAYS = IDAY_CUR-1+31
  CASE(3)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS
  CASE(4)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31
  CASE(5)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30
  CASE(6)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31
  CASE(7)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31+30
  CASE(8)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31+30+31
  CASE(9)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31+30+31+31
  CASE(10)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31+30+31+31+30
  CASE(11)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31+30+31+31+30+31
  CASE(12)
    IDAYS = IDAY_CUR-1+31+28+ILEAPS+31+30+31+30+31+31+30+31+30
END SELECT
!
IYEARS = IYEAR_CUR-TPREFERENCE_DATE%TDATE%YEAR
IF (IYEARS<0) THEN
  CALL PRINT_MSG(NVERB_WARNING,'GEN','DATETIME_TIME2REFERENCE', &
                 'input year is smaller than reference year => result could be invalid')
END IF
!
!Compute number of years + number of leap days from reference date
ILEAPS = IYEARS/4            ! 1 leap year every 4 years
ILEAPS = ILEAPS-(IYEARS/100) ! multiple of 100 are not leap years
ILEAPS = ILEAPS+(IYEARS/400) ! multiple of 400 are leap years
!
!Compute number of days since reference date
IDAYS = IDAYS + 365*IYEARS + ILEAPS
!
PDIST = REAL(IDAYS*(60*60*24))+ZSEC
!
END SUBROUTINE DATETIME_TIME2REFERENCE
!
!
SUBROUTINE DATETIME_DISTANCE(TPDATEBEG,TPDATEEND,PDIST)
!
!Compute distance (in seconds) between 2 dates
!
TYPE(DATE_TIME), INTENT(IN)  :: TPDATEBEG
TYPE(DATE_TIME), INTENT(IN)  :: TPDATEEND
REAL,            INTENT(OUT) :: PDIST
!
REAL :: ZDISTBEG, ZDISTEND
!
CALL DATETIME_TIME2REFERENCE(TPDATEBEG,ZDISTBEG)
CALL DATETIME_TIME2REFERENCE(TPDATEEND,ZDISTEND)
!
PDIST = ZDISTEND-ZDISTBEG
!
END SUBROUTINE DATETIME_DISTANCE
!
SUBROUTINE DATETIME_CORRECTDATE(TPDATE)
!
! Correct the date if not in the correct interval
! Change the date if time is <0 or >=86400 s
! or if day is not a valid day for the current month
! or if month<1 or >12
!
TYPE(DATE_TIME), INTENT(INOUT)  :: TPDATE
!
INTEGER :: IDAYS                           !Number of days to add
INTEGER :: IDAY_CUR, IMONTH_CUR, IYEAR_CUR !Currrent day, month and year
INTEGER :: IMONTH_LGT                      !Number of days in a month
LOGICAL :: GKO
REAL    :: ZSEC                            !Current time of the day (in seconds)
!
IYEAR_CUR  = TPDATE%TDATE%YEAR
IMONTH_CUR = TPDATE%TDATE%MONTH
IDAY_CUR   = TPDATE%TDATE%DAY
ZSEC = TPDATE%TIME
! print *,'DATETIME_CORRECTDATE in: ',IYEAR_CUR,IMONTH_CUR,IDAY_CUR,ZSEC
!
CALL DATETIME_GETMONTHLGT(IYEAR_CUR,IMONTH_CUR,IMONTH_LGT)
IF (TPDATE%TIME<0. .OR. TPDATE%TIME>=86400. .OR. &
    IDAY_CUR<1     .OR. IDAY_CUR>IMONTH_LGT .OR. &
    IMONTH_CUR<1   .OR. IMONTH_CUR>12            ) THEN
  GKO = .TRUE.
ELSE
  GKO = .FALSE.
END IF
!
IF (TPDATE%TIME<0.) THEN
  !Number of days to remove
  IDAYS = INT(TPDATE%TIME/86400.)-1
ELSE IF (TPDATE%TIME>=86400.) THEN
  !Number of days to add
  IDAYS = INT(TPDATE%TIME/86400.)
ELSE
  IDAYS = 0
END IF
!
!Correct time
ZSEC = ZSEC - IDAYS * 86400.
!
!Correct date
DO WHILE (GKO)
  IDAY_CUR = IDAY_CUR + IDAYS
  !
  !Check if year changed
  IF (IMONTH_CUR>12) THEN
    IYEAR_CUR = IYEAR_CUR + (IMONTH_CUR-1)/12
    IMONTH_CUR = MOD(IMONTH_CUR-1,12)+1
  ELSE IF (IMONTH_CUR<1) THEN
    IYEAR_CUR = IYEAR_CUR + IMONTH_CUR/12 - 1
    IMONTH_CUR = 12+MOD(IMONTH_CUR,12)
  END IF
  !
  CALL DATETIME_GETMONTHLGT(IYEAR_CUR,IMONTH_CUR,IMONTH_LGT)
  !
  !Check if month changed
  IF (IDAY_CUR<=IMONTH_LGT .AND. IDAY_CUR>=1) THEN
    IDAYS = 0
  ELSE IF (IDAY_CUR>IMONTH_LGT) THEN
    IMONTH_CUR = IMONTH_CUR + 1
    IDAYS = IDAY_CUR-IMONTH_LGT
    IDAY_CUR = 0
  ELSE !IDAY_CUR<1
    IMONTH_CUR = IMONTH_CUR - 1
    !Check if year changed
    IF (IMONTH_CUR<1) THEN
      IMONTH_CUR = 12
      IYEAR_CUR = IYEAR_CUR - 1
    END IF
    CALL DATETIME_GETMONTHLGT(IYEAR_CUR,IMONTH_CUR,IMONTH_LGT)
    IDAYS = IDAY_CUR
    IDAY_CUR = IMONTH_LGT
  END IF
  !
! print *,'DATETIME_CORRECTDATE du2:',IYEAR_CUR,IMONTH_CUR,IDAY_CUR,ZSEC,IDAYS
  IF (IDAYS==0      .AND.                            &
      IDAY_CUR>=1   .AND. IDAY_CUR<=IMONTH_LGT .AND. &
      IMONTH_CUR>=1 .AND. IMONTH_CUR<=12             ) GKO=.FALSE.
END DO
! print *,'DATETIME_CORRECTDATE out:',IYEAR_CUR,IMONTH_CUR,IDAY_CUR,ZSEC
!
TPDATE%TDATE%YEAR  = IYEAR_CUR
TPDATE%TDATE%MONTH = IMONTH_CUR
TPDATE%TDATE%DAY   = IDAY_CUR
TPDATE%TIME        = ZSEC
!
END SUBROUTINE DATETIME_CORRECTDATE
!
!
SUBROUTINE DATETIME_GETMONTHLGT(KYEAR,KMONTH,KLGT)
!
INTEGER, INTENT(IN)  :: KYEAR
INTEGER, INTENT(IN)  :: KMONTH
INTEGER, INTENT(OUT) :: KLGT
!
SELECT CASE(KMONTH)
  CASE(1,3,5,7,8,10,12)
    KLGT = 31
  CASE(2)
    IF ( ((MOD(KYEAR,4)==0).AND.(MOD(KYEAR,100)/=0)) .OR. (MOD(KYEAR,400)==0)) THEN
      KLGT = 29
    ELSE
      KLGT = 28
    END IF
  CASE(4,6,9,11)
    KLGT = 30
  CASE DEFAULT !Not an error (useful for DATETIME_CORRECTDATE)
    KLGT = 0
END SELECT
!
END SUBROUTINE DATETIME_GETMONTHLGT
!
!
FUNCTION DATETIME_LT(TPT1, TPT2) RESULT (OLT)
IMPLICIT NONE
LOGICAL :: OLT
TYPE(DATE_TIME), INTENT(IN) :: TPT1, TPT2
!
! TRUE if TPT1 .LT. TPT2
!
!
IF ( TPT1%TDATE%YEAR .EQ. TPT2%TDATE%YEAR ) THEN
  IF ( TPT1%TDATE%MONTH .EQ. TPT2%TDATE%MONTH ) THEN
    IF ( TPT1%TDATE%DAY .EQ. TPT2%TDATE%DAY ) THEN
      OLT = TPT1%TIME .LT. TPT2%TIME
    ELSE
      OLT = TPT1%TDATE%DAY .LT. TPT2%TDATE%DAY
    END IF
  ELSE
   OLT = TPT1%TDATE%MONTH .LT. TPT2%TDATE%MONTH
  END IF
ELSE
  OLT = TPT1%TDATE%YEAR .LT. TPT2%TDATE%YEAR
ENDIF
!
END FUNCTION DATETIME_LT
!
!
FUNCTION DATETIME_GE(TPT1, TPT2) RESULT (OLT)
IMPLICIT NONE
LOGICAL :: OLT
TYPE(DATE_TIME), INTENT(IN) :: TPT1, TPT2
!
! TRUE if TPT1 .GE. TPT2
!
OLT = .NOT.DATETIME_LT(TPT1,TPT2)
!
END FUNCTION DATETIME_GE
!
END MODULE MODE_DATETIME