Simple calendar class implemented in PHP, calendar implemented in php_PHP tutorial

date_default_timezone_set("etc/gmt-8");
header("Content-type: text/html; charset=utf-8");
class calendar{
var $t = array();
var $datesofmonth = array('1'=>'31','2'=>'28','3'=>'31','4'=>'30','5'= >'31','6'=>'30','7'=>'31','8'=>'31','9'=>'30','10'= >'31','11'=>'30','12'=>'31');
var $y,$m,$d;
function set($time){
$this->t = getdate($time);
$this->y = $this->t['year'];
$this->m = $this->t['mon'];
$this->d = date('d',$time);
}
function isrun(){
return ($this->y%400==0 || ($this->y%4==0 && $this->y%100==0)) ? 1 : 0;
}
function first(){
$time = mktime(0,0,0,$this->m,1,$this->y);
$time = getdate($time);
return $time['wday'];
}
function html(){
$isrun = $this->isrun();
$this->datesofmonth[2] = $isrun==1 ? 29: 28;
$html .= "n";
$html .= "n" ;
$html .= "jb51.netn";
$html .= "n";
$first = $this->first();
for($i=0; $i<$first; $i++){
$html .= "";
}
$count = $this->datesofmonth[$this->m]+$first;
for ($i=1; $i<= $this->datesofmonth[$this->m]; $i++){
$style = $i==$this->d ? ' style="color:red;font-weight:bold;"' : '' ;
$html .= "";
if (($i==7%$first || ($i+$first)%7==0) && $i<$count){
$html .= "n";
}
}
$count = 7-$count%7;
if ($count<7){
for ($i=0; $i<$count; $i++){
$html .= "";
}
}
$html .= "n";
$html .= "

Previous month	{$this-> ;y}year{$this->m}month					next month
Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
	$i

n";
return $html;
}
}
$calendar = new calendar();
$calendar->set(time());
echo $calendar->html();