function GMTToLocalTime(GMTTime: TDateTime): TDateTime;
var
  GMTST: Windows.TSystemTime;
  LocalST: Windows.TSystemTime;
begin
  SysUtils.DateTimeToSystemTime(GMTTime, GMTST);
  SysUtils.Win32Check(
    Windows.SystemTimeToTzSpecificLocalTime(
      nil, GMTST, LocalST
    )
  );
  Result := SysUtils.SystemTimeToDateTime(LocalST);
end;
//delphi/2171