in PHP?

codice:
$periodi=array("07,14"=>"mattina","14,21"=>"pomeriggio","21,07"=>"notte");
foreach($periodi as $chiave => $valore){
	$temp=explode(",",$chiave);
	if ($temp[0] < date("H") && date("H") < $temp[1])
		echo "<img src=\"images/".$valore.".jpg\" border=\"0\">\n";
}