[qop]

There is no reason to sleep more than 8-9.5hrs. If you are sleeping more than this, see a doctor and see what kind of hormones are not balanced.

It's probably not as bad as undersleeping to oversleep, but it's not how your body is supposed to work.

[tzar]

More than 8, or more than 9.5? Which is it?

[qop]

It's a range depending on other aspects.

Or do you think the human body ticks down 480 minutes exactly?