I once saw a sentence reading "When are you open until?" which made enough sense to me to understand it. Later, I tried to come up with sentences having a similar structure; but, no matter what sentences I came up with, they all sounded weird. Here's one:
"When are you going to school until?" (I'd appreciate it if you'd let me know if this is correct)
I was wondering whether there was a grammatical rule for these kinds of sentences.