Let’s say you had an array as following :

$time = array ("0600", "0000", "1200", "1800");

but you wanted it to be shown as

  1. 0000
  2. 0600
  3. 1200
  4. 1800

Use asort function..

asort ($time);

But you might also want to reverse order it.
Which is to show the latest possible date and time ..

arsort ($date_time_list);

Reference :
http://www.php.net/manual/en/function.asort.php
http://www.php.net/manual/en/function.arsort.php