So I know how to code it with days to expiry but am unsure as to how to code it using two separate dates, for instance, 9/14/04 to 3/21/14. Any advice would be great. Is there a similar problem in the c++ program? Thanks!
You mean you want the trading date to be 9/14/04 but the expiry of the option to be 3/21/14?
You'll need to use a date library and handle holidays appropriately to retrieve the DCF of the time to expiry?