FUNCTION scan_grib_date, num, recstart
;
;
  compile_opt idl2, strictarrsubs
;
  nrec =  n_elements(recstart)
  dates = lonarr(nrec)
;
  FOR i = 0L,nrec-1 DO BEGIN
    offset = recstart[i]
    a = assoc(num, bytarr(1, /nozero), offset+8-1)
    dates[i] = (a[13]+100L*(a[25]-1))*10000L+a[14]*100L+a[15]
  ENDFOR
;
  RETURN, dates
END