public boolean isDateEnabled(UTCDate date) {
        assert isDateVisible(date) : date + " is not visible";
        return getView().isDateEnabled(date);
    }
Is the visible date enabled?

@param date the date, which must be visible
@return is the date enabled?
stroom-core-client-widget/src/main/java/stroom/widget/datepicker/client/CustomDatePicker.java