code: function(value, sendUpdatedEvt) {
        var values = [];
        
        // !value catches "" (empty field), and invalid dates
        if(!value || !lang.isFunction(value.getTime) || !lang.isNumber(value.getTime()) ) {
           values[this.monthIndex] = "";
           values[this.yearIndex] = "";
           values[this.dayIndex] = "";
        } else {
           for(var i = 0 ; i < 3 ; i++) {
              values.push( i == this.dayIndex ? value.getDate() : (i==this.yearIndex ? value.getFullYear() : value.getMonth()+1 ) );
           }
        }
        inputEx.DateSplitField.superclass.setValue.call(this, values, sendUpdatedEvt);
     }
docs: Set the value. Format the date according to options.dateFormat
  @param {Date} val Date to set
  @param {boolean} [sendUpdatedEvt] (optional) Wether this setValue should fire the updatedEvt or not (default is true, pass false to NOT send the event)