We've always run on contract. The only children whose contracts are written to the tee, is the child who is here late at night. We don't charge hourly but by they day. So my family of 3 F-Sun pays 135 daily.
Our contracts are for 8 hours daily + 1 hour of travel. If a parent picks up late they are charged- 20$ per every portion of 15 minutes they are late- curbs their shenanigans quickly
we had a mom who called asking to pick her kid up 3 hours late! we said no, she did it anyway, needless to say she was not happy with her late fee of 240 and pulled shortly thereafter.