The example demonstrates how to customize a day in the calendar - its background
color and text content using the client- and server-side DayRender event.
The server-side DayRender event is fired after the generation of every calendar cell
object and just before it gets rendered to the client. It is the last place
where changes to the already constructed calendar cells can be made.
The client-side DayRender event is fired for every calendar day cell when the calendar
is rendered as a result of client-side navigation. This event can be used to apply final changes
to the output (content and visual styles) just before the content is displayed.