That's would actually be extremely usefull. Just using this as extra time in case you are late is already extremely beneficial, you can also use it to practice anything without bothering anyone and without the need of a studio or anything like that.
The only downside of this is that if you aren't careful you will probably end up depending on it rather than use it when it truly is neccesary, if you have a somewhat infinite amount of time at your disposal, you are likely going to be lax on your homework and will often end up having to use it when it could have been avoided. And there is no immediate penalty for doing that because you won't realize you are aging, you are just going to end up at the end of your life and realise one day that you are way older than everyone else.
I am not sure I have the self control to use something like this so I think I would leave it despite how usefull it is.
SQ