In a recent project I had the need to have multiple objects tied a single date picker pop-up. What I was really going for was a DIV field to show the date so it was true read only and to stuff the value into a hidden text field as well.

I needed to use it in multiple places and it needed to be flexible for future uses, so I came up with this quick package YAHOO.EGPS.Utils.DatePicker. It allows you to choose multiple targets (for the resulted value) and multiple triggers that will make the date-picker "pop-up".

DatePicker.register(ActionItems(s), target(s), minDate, maxDate);

Download the Code Here (version 1.0)

Example Usage
    var dp1;
    var dp2;
    function initDatePicker() {
        var DatePicker = new YAHOO.AMC.Utils.DatePicker();

        // Register the triggers and targets
        dp1 = DatePicker.register(
            ['editEventForm_fDate1','date1PickerImg'],
            [document.forms.editEventForm.date1, 'editEventForm_fDate1']
        );

        var validate = function(type, args, obj) {
            validate_dates(
                document.forms.editEventForm.date1,
                document.forms.editEventForm.date2,
                dp2
            );
        }

        // Subscribe to the selecteEvent event and run validation, not included in this example
        dp1.selectEvent.subscribe(validate);
    }
   
    // ADD the initDatePicker function to the onDOMReady
    YAHOO.util.Event.onDOMReady(initDatePicker);

Download the Code Here (version 1.0)