You can attach several handlers to the same event and detach them using two respective methods:
attachEvent() - to attach event
var myEvent = myCalendar.attachEvent("onClick", function(){
// event handler code
});
detachEvent() - to detach event
myCalendar.detachEvent(myEvent);
onBeforeChange - fires before the user starts to change month, year or time in the selector
onClick - fires after the user selects a date
onChange - fires when the user changes month, year or time in the selector
onShow - fires when the calendar becomes visible (useful when attached to an input)
onHide - fires when the calendar becomes hidden (useful when attached to an input)
onMouseOver - fires when the user moves the mouse cursor over the specified date
onMouseOut - fires when the user moves the mouse cursor out from the specified date
onPopupShow - fires when popup becomes visible (user move mouse over cell with tooltip)
onPopupHide - fires when popup becomes hidden (user move mouse out from cell with tooltip)