ON SCHEDULE MAINTANENCE; any schedule maintance; July 31th

This is from a Richmond Subaru advertisement found in 24H Vancouver on July 16, 2010. Maintanence is a nice try, but it's maintenance. It's clear they didn't even try with maintance. I would think that both cases of schedule should be scheduled. Finally, the cherry on top: July 31th (July thirty-firth?) should be July 31st. There are 10 coupons in the ad and they all expire on July 31th, 2010.