Addtional date constraints

I have a need for much tighter control over what dates can be entered beyond the +/- years. In my case I would just like the user to enter todays date or a few days in the past but nothing in the future. So it's not just for display but actually prohibit any date outside the parameters.

I could also see cases where you may want the user to only enter a future date. Perhaps an interface that let you enter in the number of days in the past, from today's date and a separate field for how many days in the future. A zero for both would only let the user enter today's date. Also perhaps you could add in two checkboxes, one if it affects just the display and a second one to physically restrain the days, i.e. not permit user to enter outside the parameters.

Would be real nice if in the calendar the days that could be selected were in a different color so the user would have the visual cue of what date are outside the range.

thank you for the consideration, mark