If set to true, the event renders and remains selectable, but cannot be edited, removed, moved, or resized. The Scheduler does not start edit or remove API and UI actions for the event, and move and resize interactions stop before their event chains. As a result, the edit, save, cancel, remove, moveStart, move, moveEnd, resizeStart, resize, and resizeEnd events are unavailable for the readonly event. Scheduler-level add, change selection, and navigate behavior remains available.

Example - create a readonly event

<script>
var event = new kendo.data.SchedulerEvent({
    id: 1,
    title: "Maintenance Window",
    start: new Date("2013/4/4 12:00"),
    end: new Date("2013/4/4 13:00"),
    isReadonly: true
});
</script>