// passage time
var pass = 48;

// 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') == 'new' ||
spans[i].getAttribute('className') == 'new') {
if (spans[i].childNodes[0]) {
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';
}
}
}
}