I'm thrilled to see you are an excel nerd like me! You are very correct regarding the 2031 end days, should be 2013. Unfortunately I don't have my spreadsheet with me today, so can't easily check up on the other qs.
I will be back at home late tonight, so can make updates then, or please feel free to input the changes to the wiki too.
Thanks very much for date checking!
Fixed the 2031 expiration years. We can only hope to have such long expiring coupons! Let me know about the rest and I can fix them (or you can as well)
Meaning of username: Deuteronomy 33:4