Call update() on the client side to immediately update the calendar after changing the properties.
Note that the server-side rendering event handlers (such as BeforeEventRender, BeforeCellRender, BeforeTimeHeaderRender, BeforeResHeaderRender render) will not be called. For a server-side assisted update, please use CommandCallBack.
Changing a Date (Example)
dps.startDate = "2013-05-01"; dps.update();
Remember to have the events preloaded or to load them manually using events.add().