Hi Amadeu,
Thank you for writing us.
The setDate method of the Date object sets the Day part of the Date only.
To add a special date, you can use the following code:
var date1 = new Date(2011, 11, 20); // Add special dates by invoking the addSpecialDate method. $("#jqxWidget").jqxCalendar('addSpecialDate', date1, '', 'Special Date1');
The above code adds a special date which is year: 2011, month: december, day: 20
Hope this helps you.
Please feel free to write us, if you have any additional questions.
Best Regards,
Peter Stoev