;**************************************************************
; routine to calculate the initial fractional hour and initial 
; fractional julian day from the number of seconds since 1970
;**************************************************************
pro ijday_ihrfrac_fm_numsec, num_sec, time_offset, real_hh, jday, yy, mm, dd, hh, mi, ss

;num_sec = basetime
;time_offset = seconds since basetime

num_sec=long(num_sec)+long(time_offset[0])
time_offset=time_offset-time_offset[0]

yy=1969
sec_count=0D
while (sec_count le num_sec) do begin
  sec_count=double(sec_count)+double(31536000) ;add seconds in a year
  yy=yy+1
  ;check to see if it is a leap year, and if so, add extra day
  check4=(yy) mod 4
  check100=(yy) mod 100
  check400=(yy)mod 400
  if (  (check4 eq 0 and check100 ne 0) or (check400 eq 0) ) then begin  ;leap years
    sec_count=double(sec_count)+double(86400)  ;add extra day
    ;print,'found leap year check',yy
  endif
endwhile
sec_count=double(sec_count)-double(31536000)  ;substract off, went over
;check to see if it is a leap year, and if so, subtract  extra day
check4=(yy) mod 4
check100=(yy) mod 100
check400=(yy)mod 400
if (  (check4 eq 0 and check100 ne 0) or (check400 eq 0) ) then begin  ;leap years
  sec_count=double(sec_count)-double(86400)
  ;print,'subtracted extra day',yy
endif
;**************************************************************
;claculate Julian Date from the remainder of the seconds
;Julian Date is the number of fractional days since Jan 1.
;**************************************************************
jday=((double(num_sec-sec_count))+time_offset)/86400.
;
;  Find the month, day and year for each
;
ddd=make_array(n_elements(jday),/float,value=-9999)
mmm=make_array(n_elements(jday),/float,value=-9999)
yyy=make_array(n_elements(jday),/float,value=-9999)
;
;  Assign values for the first jday value
;
dd=1
mm=1
for j=1,fix(jday[0]) do begin
  dtgincre_day, dd, mm, yy, 1
endfor

result=where(jday ge fix(jday[0]) and jday lt fix(jday[0]+1),count)
if count ne 0 then begin
  ddd[result]=dd
  mmm[result]=mm
  yyy[result]=yy
endif
;
;  If the data crosses multiple days, assign value for the next jday
;
numjulday=fix(jday[n_elements(jday)-1])-fix(jday[0])  ;number of julian days to loop through
jday_1=fix(jday[0]+1)
jday_2=fix(jday[0]+2)

for k=1,numjulday+1 do begin
  result_days=where(jday ge jday_1 and jday lt jday_2,count)
  if count ne 0 then begin
    dd=1
    mm=1
    for j=1,jday_1 do begin
      dtgincre_day, dd, mm, yy, 1
    endfor
    if yy gt yyy[result_days[0]-1] then begin 
      jday=jday-365.0
      jday_1=fix(jday[result_days[0]])
      jday_2=fix(jday_1+1.0)
    endif 

    result=where(jday ge jday_1 and jday lt jday_2,count)
    if count ne 0 then begin
      ddd[result]=dd
      mmm[result]=mm
      yyy[result]=yy
    endif
  endif
  jday_1=jday_1+1.0
  jday_2=jday_2+1.0
endfor
;
;  Return negative jday values to positive
;
result=where(jday lt 0,count)
if count gt 0 then jday[result]=jday[result]+365.0
;
;  Rename the arrays
;
yy=yyy
mm=mmm
dd=ddd
;
;  Calculate hour min sec
;
real_hh=((jday-(float(fix(jday))))*24.)
real_mi=((real_hh-(float(fix(real_hh))))*60.)
real_sc=((real_mi-(float(fix(real_mi))))*60.)
hh=fix(real_hh)
mi=fix(real_mi)
;ss=fix(real_sc)
ss=round(real_sc)
result=where(ss eq 60,count)
if count gt 0 then begin
  mi[result]=mi[result]+1
  ss[result]=0
endif
result=where(mi eq 60,count)
if count gt 0 then begin
  hh[result]=hh[result]+1
  mi[result]=0
endif
result=where(hh gt 24,count)
if count gt 0 then begin
  print,'hours are wrong in ijday'
  stop
endif

end