Not a school night

Setting: Max has a rocket ship tent in his room. On non-school nights (usually) weekends, he can sleep in the tent if he wishes (usually does). This week one of his school classes was still out for Christmas break. The following transpired last night (Tuesday) during our bedtime routine.
Max: "Mom, can I sleep in my tent?"
Mom: "No Max. Tonights a school night."
Max: "It's not a school night, it's a speech night!" (he had speech therapy today, but not his normal school class)