year datepicker problem

I trying to define a availability calendar using the ui datepicker and
inspired in an example on ui site.
The problem is that i can't figure how to use the year in this
example with the beforeShowDay .
please take a look at http://realferias.com/datepik.asp?cod_casa=15.
you will see that the same day is in red in every year and i just
want to filter the years also. thank you .