Hey

I'm calculating the success of whether coupons work or not and would also like to show what times the coupon worked.

Like on Amazon.com Coupon Codes - all coupons, discounts and promo codes for amazon.com

If you check out the coupon they have an image like this:


I imagine that is showing at what times since the coupon was added it was working, so at first it was working but then it started to get reported as not working..

Would it be hard to create something like this and how would I go about doing it?

Right now in my database I am storing what couponid the user rates, whether it works (yes/no) and what rating id theres is, I assume I'd have to add the date when it was rated as well