Is this sentence grammatically correct?

1 He wakes up as soon as the alarm clock rings OFF mornings.

I'm not sure if the preposition 'OFF' is correct or not. If not, what preposition should I use?
Update: I have to fill in the blanks....... rings ___ mornings. Does it make sense if I say: He wakes up as soon as the alarm clock rings IN mornings.
13 answers 13