Array
(
[0] => Array
(
[dateTime] => 2011-10-18 0:0:00
[chanl1] => 20.7
Using uasort() with a custom sort callback should do it:
function cmp($a, $b) {
if ($a['dateTime'] == $b['dateTime']) {
return 0;
}
return ($a['dateTime'] < $b['dateTime']) ? -1 : 1;
}
uasort($arr, 'cmp');
uasort() preserves your array's keys, you can use usort() instead if you don't need that to happen.