WinForm MonthCalendar/DateTimePicker min and max date

I’m wondering if somebody can shed some light on an issue. When I’m in designer and add a MonthCalendar object to a form and set the min and max date, the designer blanks the dates that are not within range. however when I run the form, it shows all dates and just doesnt let you select them. I’m certain it must be some runtime option but I cannot figure out what it could be