简单的PHP日历算法

下面是一个简单的php日历算法，希望对大家有所帮助

if (function_exists('date_default_timezone_set')) {  
     date_default_timezone_set('Asia/Chongqing');  
 }  
 $date = isset($_GET['date']) ? $_GET['date'] : date('Y-m-d');  
 $date = getdate(strtotime($date));  
 $end = getdate(mktime(0, 0, 0, $date['mon'] + 1, 1, $date['year']) - 1); 
 $start = getdate(mktime(0, 0, 0, $date['mon'], 1, $date['year']));  
 $pre = date('Y-m-d', $start[0] - 1);  
 $next = date('Y-m-d', $end[0] + 86400);  
 $html = '<table border="1">';  
 $html .= '<tr>';  
 $html .= '<td><a href="http://www.php1.cn/">  $html .= '<td colspan="5">' . $date['year'] . ';' . $date['month'] . '</td>';  
 $html .= '<td><a href="http://www.php1.cn/">  $html .= '</tr>';  
 $arr_tpl = array(0 => '', 1 => '', 2 => '', 3 => '', 4 => '', 5 => '', 6 => ''); 
 $date_arr = array();  
 $j = 0;  
 for ($i = 0; $i < $end['mday']; $i++) {  
     if (!isset($date_arr[$j])) {  
         $date_arr[$j] = $arr_tpl;  
     }  
     $date_arr[$j][($i+$start['wday'])%7] = $i+1;  
     if ($date_arr[$j][6]) {  
         $j++;  
     }  
 }  
 foreach ($date_arr as $value) {  
     $html .= '<tr>';  
     foreach ($value as $v) {  
         if ($v) {  
             if ($v == $date['mday']) {  
                 $html .= '<td><b>' . $v . '</b></td>';  
             } else {  
                 $html .= '<td>' . $v . '</td>';  
             }  
         } else {  
             $html .= '<td>&nbsp;</td>';  
         }  
     }  
     $html .= '</tr>';  
 }  
 $html .= '</table>';  
 echo $html;