You could probably accomplish this using the IUIElementDrawFilter interface. The visual appearance of the TimeSlot descriptor is realized through the Infragistics.Win.UltraWInSchedule.DayView.TimeSlotDescriptorUIElement. You could use the IUIElementCreationFilter interface to remove the HourUIElement and MinuteUIElement elements that appear by default (as immediate children of the TimeSlotDescriptorUIElement), and add a TextUIElement instead, with the Text property of the TextUIElement set to the caption you want to display. One thing to note is that the TimeSlotDescriptorUIElement exposes a property, SelectableItem, which will return the first TimeSlot associated with that descriptor; I mention this because this is the only way to get an association between the descriptor and a TimeSlot, and you might need this information depending what information you need for your caption.