const
 SecPerDay = 86400;
 SecPerHour = 3600;
 SecPerMinute = 60;
function SecondToTime(const Seconds: Cardinal): Double;
var
 ms, ss, mm, hh, dd: Cardinal;
begin
 dd := Seconds div SecPerDay;
 hh := (Seconds mod SecPerDay) div SecPerHour;
 mm := ((Seconds mod SecPerDay) mod SecPerHour) div SecPerMinute;
 ss := ((Seconds mod SecPerDay) mod SecPerHour) mod SecPerMinute;
 ms := 0;
 Result := dd + EncodeTime(hh, mm, ss, ms);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
 label1.Caption := DateTimeToStr(Date + SecondToTime(86543));
end;