Another one of the many properties of the control is a toggle to display week numbers. This is most probably very useful when writing financial applications. It would be useful in other situations too if the week numbering could be customized. For example, here in Chicago, the school system considers week one to be the week of September 1, and week forty is the second or third week of June, when school lets up.
A couple of other useful controls in the package are the AnniversaryTextBox and the MonthYearTextBox. These controls allow entry of a month and date (an anniversary, for example), and just the month and year, respectively.