/**
 * @example     truncDate($date[, $min[, $max]]);
 * @param $date Date    Datum das gekürzt werden sollte
 * @param $min  String  Schlüssel der unteren Limite
 * @param $max  String  Schlüssel der obeen Limite
 * @return      Date    gekürztes Datum
 */
function truncDate($date, $min = 'mday', $max = 'year'){
	$order = array('seconds', 'minutes', 'hours', 'mday', 'mon', 'year',);
	$minId = array_search($min, $order);   
	$maxId = array_search($max, $order);   
	
	$dateInfo = getdate($date);
	
	$keys = array_flip(array_slice($order, $minId, $maxId-$minId+1, true));
	$parts = array_intersect_key($dateInfo, $keys);
	$defaults = array_fill_keys(array_keys($dateInfo), 0);   
	$parts = array_merge($defaults, $parts);
  
	return mktime($parts['seconds'], $parts['minutes'], $parts['hours'], $parts['mon'], $parts['mday'], $parts['year']);   
}