I think I'm not the only one having this problem. Whenever I try to apply a BeforeShowDay a new CSS class, the content of the "special date" is not being modified. I tried changing the default theme, adding a new class, but this is affecting only the outside border and not the inside content. Using Firebug I found that the html code being printed is the following: <td class=" ui-state-content ui-state-anulados" onclick="DP_jQuery.datepicker._selectDay('#datepicker',9,2009, this);return false;" title="Paddle"> <a class="ui-state-default" href="#">16</a> </td> So, my class would be ui-state-content ui-state-anulados but I notice that the ui-state-default class is being applied automatically and I suspect that this may be the problem. I really don't know how to solve this. I've been looking inside ui.datepicker.js code and I think I found the line that is giving me this problems. It is line number 1394 and it has the following code. (ui.datepicker.js) (unselectable ? '<span class="ui-state-default">' + printDate.getDate() + '</span>' : '<a class="ui-state-default' + Any clues on how this can be done? Thanks in advance. Manuel.-