días en el mes actual
function daysInThisMonth() {
var now = new Date();
return new Date(now.getFullYear(), now.getMonth()+1, 0).getDate();
}
Silly Sloth
function daysInThisMonth() {
var now = new Date();
return new Date(now.getFullYear(), now.getMonth()+1, 0).getDate();
}