Use the Images method of the control to change the Images collection at runtime. The Image property is 1 based. If the index is not found into Images collection, no image is displayed on cell's date.  If the date's image is not visible, use the AutoSize, FixedCellHeight and FixedCellWidth properties to increase the cell size.  The cell size show be larger than (16,16) in order to display images. The Images method sets the control's handle image list. The ImageSize property defines the size (width/height) of the icons within the control's Images collection.