/**
* Calculates the date of the Nth weekday of the month,
* such as the second Saturday of January 2000.
*
* $occurance: 1=first, 2=second, 3=third, etc.
* $day_of_week: 0=Sunday, 1=Monday, etc.
*
*/
function get_n_week_day_of_month($occurance, $day_of_week, $date = null)
{
$this->_check_date(&$date);
$year = $date->year;
$month = $date->month;
$DOW1day = ($occurance - 1) * 7 + 1;
$d = date::create($year, $month, $DOW1day);
$DOW1 = $d->get_day_of_week();
$wdate = ($occurance - 1) * 7 + 1 + (7 + $day_of_week - $DOW1) % 7;
if ($wdate > $this->get_days_in_month($date)) {
return null;
} else {
return date::create($year, $month, $wdate);
}
}
