- date: documentation ( source)
<?php
$today = new DateTime(date('Y-m-d'));
$today->modify('+1 day');
echo $today->format('Y-m-d H:i:s');
$dateFrom = new DateTime("2013-02-15 23:00:00");
echo $dateFrom->format('Y-m-d H:i:s');
$dateTo = new DateTime("2013-02-17 23:00:00");
echo $dateTo->format('Y-m-d H:i:s');
if($today >= $dateFrom && $today <= $dateTo) {
echo "true";
} else {
echo "false";
}