Datepicker : custom buttons ?

Datepicker : custom buttons ?

Hi,

Is it possible to add custom buttons (in my case "today" and "this week end") at the bottom of the calendar ?
More generally, how to add custom HTML code in the datepicker HTML render code ? I have created js function to add my HTML code when the calendar is created, but when the month changes, then the entire calendar is re-rendered and my function is useless.

tx,
Aurélien from France