function renew_date() {
	// passage time
	var pass = 72;
	
	// display content
	var content = 'New!!';
	 
	var currentDate = new Date(); 
	var spans = document.getElementsByTagName('span');
	for (i = 0; i < spans.length; i++) {
	    if(spans[i].getAttribute('class') == 'club_new' ||
	       spans[i].getAttribute('className') == 'club_new') {
	        time = spans[i].childNodes[0].nodeValue.split(":");
	        var entryDate = new Date(time[0], time[1]-1, time[2], time[3], time[4], time[5]); 
	        var now = (entryDate.getTime() - currentDate.getTime())/(60*60*1000); 
	        now = Math.ceil(now);
	        if(-now <= pass){
	            spans[i].innerHTML = content;
	            spans[i].style.display = 'inline';
	        }
	    }
	}
}