public function copy()
{
$date = new Date();
$date->set_year($this->_year, false);
$date->set_month($this->_month, false);
$date->set_day($this->_day, false);
$date->set_hour($this->_hour, false);
$date->set_minutes($this->_min, false);
$date->set_seconds($this->_secs, false);
return $date;
}