;******************************************************************************
; Function num_sec_ep is passed a date and time and then converts
; it to number of seconds since 1-1-1970.  This becomes the value of 
; the function
;******************************************************************************
function num_sec_ep, year, month, day, hour, minute, second

;print,'year',year,' month',month,' day',day,' hour',hour,' minute',minute,' second',second

;******************************************************************************
;Add up all the seconds from 1-1-1970 to the last completed year (or year -1)
;******************************************************************************
numyears=year-1970             ;number of whole years to sum
numsecs=0                      ;initialize numsecs to 0
for i=1,numyears do begin      ;loop throught the number of years
                               ;leap year rules
  check4=(1969+i) mod 4        ;1.years divisible by 4 are leap years,unless...
  check100=(1969+i) mod 100    ;2.years also divisible by 100 are not leap 
                               ;  years, except.......
  check400=(1969+i)mod 400     ;3.years divisible by 400 are leap years.

  if (check4 eq 0 and check100 ne 0 ) then begin
    numsecs=long(numsecs)+long(31536000)+long(86400)
    ;print,'found first leap year check ',1969+i
  endif else if (check400 eq 0 ) then begin
    numsecs=long(numsecs)+long(31536000)+long(86400)
    ;print,'found second  leap year check',1969+i
  endif else begin
    numsecs=long(numsecs)+long(31536000)
    ;print,'no leap year',1969+i
  endelse
endfor
;print,'sum sec years',numsecs

;******************************************************************************
;sum up the number of days since the first of the year until month-1
;******************************************************************************
days=fltarr(12)
days=[31,28,31,30,31,30,31,31,30,31,30,31]
if (month ge 2) then begin
  sum_day=total(days[0:month-2])
  ;print,'sum_day',sum_day
  sum_day_sec=long(86400)*long(sum_day)
  ;print,'sum_day_sec',sum_day_sec
  numsecs=long(numsecs)+long(sum_day_sec)
endif
;print,'numsecs',numsecs

;**********************************************************
;another leap year check to add another day if the current year is a leap year
;**********************************************************
check4=(year) mod 4
check100=(year) mod 100
check400=(year)mod 400
if ( ( (check4 eq 0 and check100 ne 0) or $
   (check400 eq 0)) and month gt 2 ) then begin
  numsecs=long(numsecs)+long(86400)
  ;print,'adding extra day for leap year',numsecs
endif

;***********************************************************
;add the day, hour, min, and sec
;***********************************************************
numsecs=long(numsecs)+long(86400)*long(day-1)
;print,'adding days',numsecs,long(day-1),long(86400)*long(day-1)
numsecs=long(numsecs)+long(hour)*long(3600)
;print,'adding hour',numsecs,long(hour),long(hour)*long(3600)
numsecs=long(numsecs)+long(minute)*long(60)
;print,'adding minu',numsecs,long(minute),long(minute)*long(60)
numsecs=long(numsecs)+long(second)
;print,'adding seco',numsecs,long(second)
;print,'numsecs',numsecs

return, numsecs
end