The shading part can be achieved through custom drawing. You have to set the Calendar.CustomDraw property to CustomDrawElements.DayContents, then handle the Calendar.Draw event. Below is a sample event handler body:

if (e.Element == CustomDrawElements.DayContents)
{
    // Obtain the type of the date represented by the cell
    // we are about to draw
    int type = 0;

    Rectangle b = e.Bounds;

    switch (type)
    {

	  case 0: // AM
		e.Graphics.DrawRectangle(Pens.Red, b.X, b.Y, b.Width, b.Height / 2);
		break;

	  // etc.
    }
}
 

The sample draws a red rectangle around the date cell. You can modify this part to match your particular needs.

As for the '1 item per day' restriction, you can handle the Calendar.ItemModifying event and check whether the modified item is moved within a cell which already contains another item. You can also handle the Calendar.ItemCreating event to prevent items from being interactively created in occupied cells.

Meppy

The event should be fired before the items are rendered by the control. Are you certain you specify CustomDrawElements.DayContents as a value of the Calendar.CustomDraw property?

Meppy

In this case you might have to draw the entire item yourself, since the event is fired when the item is already rendered by the control and there will be no way to draw underneath the text. You can also use semitransparent brush when drawing the triangle.

Meppy

You can turn off regular item drawing by setting the ItemSettings.EnableDefaultRendering property to State.Disabled.

Meppy