;+
; NAME:
;     JDAY2DATE
;
; PURPOSE:
;     This procedure converts julian day to date.
;
; CALLING SEQUENCE:
;     JDAY2DATE, JDAY, MO, DY, YR
;
; INPUTS:
;     JDAY      (Integer) Julian day.
;
; OUTPUTS:
;     MO        (Integer) Month of the year.
;     DY        (Integer) Day of the month.
;     YR        (Integer) Year.
;-

pro jday2date, jday, mo, dy, yr

  day_of_yr = [31,28,31,30,31,30,31,31,30,31,30,31]
  day_of_leapyr = [31,29,31,30,31,30,31,31,30,31,30,31]

  if (yr MOD 4) EQ 0 then days = day_of_leapyr $
  else days = day_of_yr
  dy = FIX(jday)
  mo = 0
  while dy GT days(mo) do begin
    dy = dy - days(mo)
    mo = mo + 1
  endwhile
  mo = mo + 1
end