ayuda datepickter

necesito bloquear todos los dias del calendario he ir activandolos a mediada que yo vaya dando los dias que quiera desbloquear tengo un codigo pero bloque los dias que uno le da el codigo es el sgte

$(document).ready(function(){


$("#datepicker1").datepicker({
beforeShowDay: nonWorkingDates,
numberOfMonths: 1,
minDate: new Date(),
firstDay: 1
});
function nonWorkingDates(date){
var day = date.getDay(), Sunday = 0, Monday = 1, Tuesday = 2, Wednesday = 3, Thursday = 4, Friday = 5, Saturday = 6;
var closedDates = [[9, 12, 2012], [9, 8, 2012]];
var closedDays = [];
for (var i = 0; i < closedDays.length; i++) {
if (day == closedDays[0]) {
return [false];
}


}
for (i = 0; i < closedDates.length; i++) {
if (date.getMonth() == closedDates[0] - 1 &&
date.getDate() == closedDates[1] &&
date.getFullYear() == closedDates[2]) {
return [false];
}
}
return [true];
}
});