jQuery datetimepicker - how to get date in javascript?

So I have a jQuery DateTimePicker v2.4.1 attached on a text input. I wanted to make it so then when the user clicks and changes the Month or Year of the picker - it would update the date within the form as this doesn't seem to be a default behavior of the plugin.

    $(timepicker).datetimepicker({
        format: "d M Y h:i A",
        step: 15,
        validateOnBlur: false, //use ValidateDateTime.js instead of jquery default
        closeOnInput: true,
        closeOnDateSelect: true,
        onClose: function() {
            var validatedDate = validateDate($(timepicker).val());
            if (validatedDate != false) {
                $(timepicker).val(validatedDate);
            }
        },
        changeMonth: true,
        changeYear: true,
        onChangeMonth: function() {
            //pop name of month into field and update calendar
            var d = $(this).datetimepicker('getDate');
            console.log(d + this.html());

            /*
            $(timepicker).datetimepicker.trigger("select.xdsoft", [d]);
            */
        }
    });

A problem that occurs is: var d = $(this).datetimepicker('getDate'); does not actually retrieve the date and just returns the datetimepicker element.

How do I get the date in js or more specifically - how could I force an update when the user clicks on a month within the drop down.