PHP Create Timestamp from String - http://stackoverflow.com/a/6501035/1703124
<?php
// m/d/y
$timestamp = strtotime('1/1/2011');
// d-m-y
$timestamp = strtotime('1-1-2011');
// Other way
if ( preg_match('/^(?P<day>\d+)[-\/](?P<month>\d+)[-\/](?P<year>\d+)$/', '1/1/2011', $matches) )
{
$timestamp = mktime(0, 0, 0, ( $matches['month'] - 1 ), $matches['day'], $matches['year']);
}