I was having the same problem, with a value like 2016-08-8, then I solved adding a zero to have two digits days, and it works. Tested in chrome, firefox, and Edge
today:function(){
var today = new Date();
var d = (today.getDate() < 10 ? '0' : '' )+ today.getDate();
var m = ((today.getMonth() + 1) < 10 ? '0' :'') + (today.getMonth() + 1);
var y = today.getFullYear();
var x = String(y+"-"+m+"-"+d);
return x;
}