I think 9:47 would be better.
You should be getting about 9 hours of sleep at that age. So if you need to get up at 7:30 am, It is a good bedtime.
I do believe that was my bedtime at that age. But the time I actually ended up in bed it was probably about 10pm.
"Experts say that during the teen years, the body's circadian rhythm (sort of like an internal biological clock) is temporarily reset, telling a person to fall asleep later and wake up later."
My oldest boy turns 51 this year. The "expert" quote above wasn't made until much more recently.
To some degree, sleep needs are individuated; and the general guidelines are sometimes too general.
Here's the website that contains that quote. The website itself is a pretty good explanation of things to consider when trying to establish sleep patterns for teenagers.
yeah maybe about Nine Forty Seven like Jaimie JT said.
Yes, it is.