int days = 1;
var newDate = new Date(Date.now() + days*24*60*60*1000);
CodePen
var days = 2;
var newDate = new Date(Date.now()+days*24*60*60*1000);
document.write('Today: ');
document.write(new Date());
document.write(' New: ');
document.write(newDate);