Another unique Telerik RadCalendar feature is the ability to control the rendering direction - you can render the content horizontally (in rows) or vertically (in columns), which gives respectively horizontal (classic) or vertical look of the calendar content. When using the Orientation property proper values for Columns and Rows should be defined, otherwise the layout will be invalid.

aspx file:
Orientation = "RenderInRows"
or
Orientation = "RenderInColumns"

codebehind:
Orientation = Orientation.RenderInRows
or
Orientation = Orientation.RenderInColumns