The only way to do it in the Lite version is to place the Scheduler inside an UpdatePanel and refresh the panel.
It is demonstrated in this tutorial (not described in the tutorial text but it is used in the sample code):
http://code.daypilot.org/16646/project-management-for-asp-net-open-source
It is refreshed using a hidden Button control which is invoked from modal.closed using __doPostBack():
function createModal() {
var modal = new DayPilot.Modal();
modal.top = 60;
modal.width = 300;
modal.opacity = 50;
modal.border = "10px solid #d0d0d0";
modal.closed = function () {
if (this.result && this.result.refresh) {
__doPostBack(id.refreshButton, '');
}
};
modal.setHeight = function (height) {
modal.height = height;
return modal;
};
modal.height = 260;
modal.zIndex = 100;
return modal;
}