Adding a date field to checkout form

Hi!

I’ve been trying to add a Birth Day field to the checkout form. I found out that, although it is not in the doc at (https://www.paidmembershipspro.com/add-ons/free-add-ons/pmpro-register-helper-add-checkout-and-profile-fields/adding-fields/), there is a “date” field type, but I could not find out how to make it show three comboboxes showing month, day and year. When I create the field with

$fields[] = new PMProRH_Field(“birthday”,”date”, array(“profile”=>true));

it is only displayed one combo to select month and two textboxes, one for day and another for year, with poor formatting. It would be nice if the docs were updated to show all the options we have to customize the displaying of the field, if any. I tried to find some help with Google, but found none about the date field type, only that it was introduced some time ago.

[]s
James