Array ( [0] => Array ( [dateTime] => 2011-10-18 0:0:00 [chanl1] => 20.7
For performance, this method using array_multisort is very efficient:
$ord = array(); foreach ($array as $key => $value){ $ord[] = strtotime($value['dateTime']); } array_multisort($ord, SORT_ASC, $array); print_r($array);