Code:

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;