php date code

<?php echo '<?xml version="1.0" encoding="UTF-8"?>'."\n" ?>

<head>

<?php
$month = ""
$month = date("m");


$spring = ""
$spring = array('3', '4', '5');
$summer = ""
$summer = array('6', '7', '8');
$fall = ""
$fall = array('9', '10', '11');
$winter = ""
$winter = array('12', '1', '2');
if($month == $spring) echo "spring.css";
if($month == $summer) echo "summer.css";
if($month == $fall) echo "fall.css";
if($month == $winter) echo "winter.css";
?>

<?php
$style="";
echo '<link rel="StyleSheet" href="'.$style.'" type="text/css" />'." \n";
?>

</head>