formato data php gg / mm / aaaa
date("d/m/Y", strtotime($str));
php convertire data da gg / mm / aaaa a aaaa-mm-gg
$date = DateTime::createFromFormat('d/m/Y', "24/04/2012");
echo $date->format('Y-m-d');
cambia il formato datetime da Y-m-d h:i: s a d-m - Y in php
$old_date = date('l, F d y h:i:s'); // returns Saturday, January 30 10 02:06:34
$old_date_timestamp = strtotime($old_date);
$new_date = date('Y-m-d H:i:s', $old_date_timestamp);
php cambia il formato della data da d/m / y a y-m-d
$var = '20/04/2012';
$date = str_replace('/', '-', $var);
echo date('Y-m-d', strtotime($date));