subroutine geth_idts (ndate, odate, idts)
implicit none
!***********************************************************************
!
! purpose - from 2 input mdates ('YYYY-MM-DD HH:MM:SS'), compute
! the time difference in seconds.
!
! on entry - ndate - the new hdate.
! odate - the old hdate.
!
! on exit - idts - the change in time in seconds.
!
!***********************************************************************
character*(*) ndate, odate
character*19 tdate
integer idts
integer olen, nlen
!
! Local Variables
!
! yrnew - indicates the year associated with "ndate"
! yrold - indicates the year associated with "odate"
! monew - indicates the month associated with "ndate"
! moold - indicates the month associated with "odate"
! dynew - indicates the day associated with "ndate"
! dyold - indicates the day associated with "odate"
! hrnew - indicates the hour associated with "ndate"
! hrold - indicates the hour associated with "odate"
! minew - indicates the minute associated with "ndate"
! miold - indicates the minute associated with "odate"
! scnew - indicates the second associated with "ndate"
! scold - indicates the second associated with "odate"
! i - loop counter
! mday - a list assigning the number of days in each month
! newhrs - the number of hours between "ndate" and 1901
! whole 24 hour days
! oldhrs - the number of hours between "odate" and 1901
!
integer yrnew, monew, dynew, hrnew, minew, scnew
integer yrold, moold, dyold, hrold, miold, scold
integer mday(12), i, newdys, olddys
logical npass, opass
integer isign
! External function:
integer, external :: nfeb
!************************* Subroutine Begin **************************
if (odate.gt.ndate) then
isign = -1
tdate=ndate
ndate=odate
odate=tdate
else
isign = 1
endif
!
! Assign the number of days in a months
!
mday( 1) = 31
mday( 2) = 28
mday( 3) = 31
mday( 4) = 30
mday( 5) = 31
mday( 6) = 30
mday( 7) = 31
mday( 8) = 31
mday( 9) = 30
mday(10) = 31
mday(11) = 30
mday(12) = 31
!
! Break down old hdate into parts
!
hrold = 0
miold = 0
scold = 0
olen = len(odate)
read(odate(1:4), '(I4)') yrold
read(odate(6:7), '(I2)') moold
read(odate(9:10), '(I2)') dyold
if (olen.ge.13) then
read(odate(12:13),'(I2)') hrold
if (olen.ge.16) then
read(odate(15:16),'(I2)') miold
if (olen.ge.19) then
read(odate(18:19),'(I2)') scold
endif
endif
endif
!
! Break down new hdate into parts
!
hrnew = 0
minew = 0
scnew = 0
nlen = len(ndate)
read(ndate(1:4), '(I4)') yrnew
read(ndate(6:7), '(I2)') monew
read(ndate(9:10), '(I2)') dynew
if (nlen.ge.13) then
read(ndate(12:13),'(I2)') hrnew
if (nlen.ge.16) then
read(ndate(15:16),'(I2)') minew
if (nlen.ge.19) then
read(ndate(18:19),'(I2)') scnew
endif
endif
endif
!
! Check that the dates make sense.
!
npass = .true.
opass = .true.
! Check that the month of NDATE makes sense.
if ((monew.gt.12).or.(monew.lt.1)) then
print*, 'GETH_IDTS: Month of NDATE = ', monew
npass = .false.
endif
! Check that the month of ODATE makes sense.
if ((moold.gt.12).or.(moold.lt.1)) then
print*, 'GETH_IDTS: Month of ODATE = ', moold
opass = .false.
endif
! Check that the day of NDATE makes sense.
if (monew.ne.2) then
! ...... For all months but February
if ((dynew.gt.mday(monew)).or.(dynew.lt.1)) then
print*, 'GETH_IDTS: Day of NDATE = ', dynew
npass = .false.
endif
elseif (monew.eq.2) then
! ...... For February
if ((dynew .gt. nfeb(yrnew)).or.(dynew.lt.1)) then
print*, 'GETH_IDTS: Day of NDATE = ', dynew
npass = .false.
endif
endif
! Check that the day of ODATE makes sense.
if (moold.ne.2) then
! ...... For all months but February
if ((dyold.gt.mday(moold)).or.(dyold.lt.1)) then
print*, 'GETH_IDTS: Day of ODATE = ', dyold
opass = .false.
endif
elseif (moold.eq.2) then
! ....... For February
if ((dyold .gt. nfeb(yrold)).or.(dyold .lt. 1)) then
print*, 'GETH_IDTS: Day of ODATE = ', dyold
opass = .false.
endif
endif
! Check that the hour of NDATE makes sense.
if ((hrnew.gt.23).or.(hrnew.lt.0)) then
print*, 'GETH_IDTS: Hour of NDATE = ', hrnew
npass = .false.
endif
! Check that the hour of ODATE makes sense.
if ((hrold.gt.23).or.(hrold.lt.0)) then
print*, 'GETH_IDTS: Hour of ODATE = ', hrold
opass = .false.
endif
! Check that the minute of NDATE makes sense.
if ((minew.gt.59).or.(minew.lt.0)) then
print*, 'GETH_IDTS: Minute of NDATE = ', minew
npass = .false.
endif
! Check that the minute of ODATE makes sense.
if ((miold.gt.59).or.(miold.lt.0)) then
print*, 'GETH_IDTS: Minute of ODATE = ', miold
opass = .false.
endif
!
! Check that the second of NDATE makes sense.
!
if ((scnew.gt.59).or.(scnew.lt.0)) then
print*, 'GETH_IDTS: SECOND of NDATE = ', scnew
npass = .false.
endif
! Check that the second of ODATE makes sense.
if ((scold.gt.59).or.(scold.lt.0)) then
print*, 'GETH_IDTS: Second of ODATE = ', scold
opass = .false.
endif
if (.not. npass) then
print*, 'Screwy NDATE: ', ndate(1:nlen)
STOP 'Error_ndate'
endif
if (.not. opass) then
print*, 'Screwy ODATE: ', odate(1:olen)
STOP 'Error_odate'
endif
!
! Date Checks are completed. Continue.
!
!
! Compute number of days from 1 January ODATE, 00:00:00 until ndate
! Compute number of hours from 1 January ODATE, 00:00:00 until ndate
! Compute number of minutes from 1 January ODATE, 00:00:00 until ndate
!
newdys = 0
do i = yrold, yrnew - 1
newdys = newdys + (365 + (nfeb(i)-28))
enddo
if (monew .gt. 1) then
mday(2) = nfeb(yrnew)
do i = 1, monew - 1
newdys = newdys + mday(i)
enddo
mday(2) = 28
end if
newdys = newdys + dynew-1
!
! Compute number of hours from 1 January ODATE, 00:00:00 until odate
! Compute number of minutes from 1 January ODATE, 00:00:00 until odate
!
olddys = 0
if (moold .gt. 1) then
mday(2) = nfeb(yrold)
do i = 1, moold - 1
olddys = olddys + mday(i)
enddo
mday(2) = 28
end if
olddys = olddys + dyold-1
!
! Determine the time difference in seconds
!
idts = (newdys - olddys) * 86400
idts = idts + (hrnew - hrold) * 3600
idts = idts + (minew - miold) * 60
idts = idts + (scnew - scold)
if (isign .eq. -1) then
tdate=ndate
ndate=odate
odate=tdate
idts = idts * isign
endif
!************************** Subroutine End ***************************
end
integer function nfeb(year)
!
! Compute the number of days in February for the given year.
!
implicit none
integer, intent(in) :: year ! Four-digit year
nfeb = 28 ! By default, February has 28 days ...
if (mod(year,4).eq.0) then
nfeb = 29 ! But every four years, it has 29 days ...
if (mod(year,100).eq.0) then
nfeb = 28 ! Except every 100 years, when it has 28 days ...
if (mod(year,400).eq.0) then
nfeb = 29 ! Except every 400 years, when it has 29 days ...
if (mod(year,3600).eq.0) then
nfeb = 28 ! Except every 3600 years, when it has 28 days.
endif
endif
endif
endif
end function nfeb