function julian(year, month, day: Integer): real;
var
 yr, mth: Integer;
 noleap, leap, days, yrs: Real;
begin
 if year < 0 then yr := year + 1 else yr := year;
 mth := month;
 if (month < 3) then
  begin
  mth := mth + 12;
  yr := yr - 1;
  end;
 yrs := 365.25 * yr;
 if ((yrs < 0) and (frac(yrs) <> 0)) then yrs := int(yrs) - 1 else yrs := int(yrs);
 days := int(yrs) + int(30.6001 * (mth + 1)) + day - 723244.0;
 if days < -145068.0 then julian := days
 else
 begin
  yrs := yr / 100.0;
  if ((yrs < 0) and (frac(yrs) <> 0)) then yrs := int(yrs) - 1;
  noleap := int(yrs);
  yrs := noleap / 4.0;
  if ((yrs < 0) and (frac(yrs) <> 0)) then yrs := int(yrs) - 1;
  leap := 2 - noleap + int(yrs);
  julian := days + leap;
 end;
end;