You can do this with my jQuery datepicker using a custom "renderCallback".
e.g. This example disables weekends and adds a class for styling those days. There are lots of other more complex examples which might help too...
$('.date-pick')
.datePicker(
{
renderCallback:function($td, thisDate, month, year)
{
if (thisDate.isWeekend()) {
$td.addClass('weekend');
$td.addClass('disabled');
}
}
}
);
Also, if you would prefer, there is a dpMonthChanged event once the calendar has re-rendered and you can loop over the contents of the calendar and do your highlighting...