mod_dates.f90 4.86 KiB
!---------------------------------------------------------------------------------------
! PREP_SYNDATA: mod_dates
!---------------------------------------------------------------------------------------
! FLEXINVERT is free software: you can redistribute it and/or modify
! it under the terms of the GNU General Public License as published by
! the Free Software Foundation, either version 3 of the License, or
! (at your option) any later version.
!
! FLEXINVERT is distributed in the hope that it will be useful,
! but WITHOUT ANY WARRANTY; without even the implied warranty of
! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
! GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License
! along with FLEXINVERT. If not, see <http://www.gnu.org/licenses/>.
!
! Copyright 2017, Rona Thompson
!---------------------------------------------------------------------------------------
!
!> mod_dates
!!
!! Purpose: Module of date functions.
!!
!---------------------------------------------------------------------------------------
module mod_dates
implicit none
contains
! --------------------------------------------------
! caldate
! --------------------------------------------------
!> caldate
!!
!! Purpose: Converts a julian date number to date
!! and time format YYYYMMDD, HHMISS
!! according to the gregorian calender
!!
! --------------------------------------------------
subroutine caldate(jdate, yyyymmdd, hhmiss)
real(kind=8), intent(in) :: jdate
integer, intent(out) :: yyyymmdd, hhmiss
integer :: yyyy, mm, dd, hh, mi, ss
integer :: julday, ja, jb, jc, jd, je, jalpha
integer, parameter :: igreg = 2299161
julday=int(jdate)
if(julday.ge.igreg) then
jalpha=int(((julday-1867216)-0.25)/36524.25)
ja=julday+1+jalpha-int(0.25*jalpha)
else
ja=julday
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)
mm=je-1
if(mm.gt.12) mm=mm-12
yyyy=jc-4715
if(mm.gt.2) yyyy=yyyy-1
if(yyyy.le.0) yyyy=yyyy-1
yyyymmdd=10000*yyyy+100*mm+dd
hh=int(24.*(jdate-float(julday))) mi=int(1440.*(jdate-float(julday))-60.*float(hh))
ss=nint(86400.*(jdate-float(julday))-3600.*float(hh))-60.*float(mi)
if(ss.eq.60) then ! 60 seconds = 1 minute
ss=0
mi=mi+1
endif
if(mi.eq.60) then
mi=0
hh=hh+1
endif
hhmiss=10000*hh+100*mi+ss
end subroutine caldate
! --------------------------------------------------
! julday
! --------------------------------------------------
!> julday
!!
!! Purpose: Converts the date and time format
!! YYYYMMDD and HHMMSS to a julian date
!! number.
!!
! --------------------------------------------------
real(kind=8) function juldate(yyyymmdd,hhmiss)
integer, intent(in) :: yyyymmdd,hhmiss
integer :: yyyy,mm,hh,dd,mi,ss
integer :: julday,jy,jm,ja
integer, parameter :: igreg=15+31*(10+12*1582)
yyyy=yyyymmdd/10000
mm=(yyyymmdd-10000*yyyy)/100
dd=yyyymmdd-10000*yyyy-100*mm
hh=hhmiss/10000
mi=(hhmiss-10000*hh)/100
ss=hhmiss-10000*hh-100*mi
if(yyyy.eq.0) print*, 'ERROR: there is no year zero'
if(yyyy.lt.0) yyyy=yyyy+1
if(mm.gt.2) then
jy=yyyy
jm=mm+1
else
jy=yyyy-1
jm=mm+13
endif
julday=int(365.25*jy)+int(30.6001*jm)+dd+1720995
if (dd+31*(mm+12*yyyy).ge.igreg) then
ja=int(0.01*jy)
julday=julday+2-ja+int(0.25*ja)
endif
juldate=dble(float(julday))+dble(float(hh)/24.)&
&+dble(float(mi)/1440.)+dble(float(ss)/86400.)
end function juldate
! --------------------------------------------------
! calceomday
! --------------------------------------------------
!> calceomday
!!
!! Purpose: Calculates number of days in a given
!! year, month. Currently only considers
!! years from 1900
!!
! --------------------------------------------------
integer function calceomday(yyyymm)
integer, intent(in) :: yyyymm
integer :: yyyy,mm
integer, dimension(12) :: leapdays,days
integer :: eomday
leapdays=(/31,29,31,30,31,30,31,31,30,31,30,31/)
days=(/31,28,31,30,31,30,31,31,30,31,30,31/)
yyyy=floor(yyyymm/100.)
mm=yyyymm-yyyy*100
if((float(yyyy)/100.).eq.float(yyyy/100)) then
if((float(yyyy)/400.).eq.float(yyyy/400)) then
eomday=leapdays(mm)
else
eomday=days(mm)
endif
else
if((float(yyyy)/4.).eq.float(yyyy/4)) then
eomday=leapdays(mm)
else
eomday=days(mm)
endif
endif
calceomday=eomday
end function calceomday
! --------------------------------------------------
end module mod_dates