<script>
// Variables
var dateHidden = document.querySelector('#date');
var d = new Date();
// Log Date plus 3 days
d.setDate(d.getDate()+3);
var month = d.getMonth()+1;
var day = d.getDate();
var output = ((''+day).length<2 ? '0' : '') + day + '/' + ((''+month).length<2 ? '0' : '') + month + '/' + d.getFullYear();
// Change date value
if (dateHidden.value == '10/10/2050') {
dateHidden.value = output;
}
</script>