One way to do this: on a hidden tab or other remote spot in your
workbook, enter the date range in a column and add the N/A at the
bottom or top. It might look like this:
11/8/2007
11/9/2007
11/10/2007
N/A

Then create a named range called DateRange (or some similar unique
name) and refer to those cells, including the N/A. When you go to set
up the data validation, in the Allow box choose "List" and in the
Source box enter the formula =DateRange.

Will that work for you?
DaveO
Eschew obfuscation