/**
* Gets the difference of two date values in sfTime::YEAR
*
* @param $other mixed timestamp, string, or sfDate object
* @return int the difference in the unit
* @author Enrique Martinez <*****@*****.**>
**/
public function diffYear($other)
{
$other_date = self::getInstance($other);
$diff = $this->getYear() - $other_date->getYear();
$date_compare = new sfDate($other_date);
$date_compare->addYear($diff);
if ($diff > 0 && $date_compare->cmp($this) > 0) {
$diff--;
}
if ($diff < 0 && $date_compare->cmp($this) < 0) {
$diff++;
}
return $diff;
}
