I have been accused by more than one here of never sleeping.
I spend what is necessary over a 16 to 18 hour day. With customers and hosting clients from Eastern Europe to Australia and New Zealand and a partner and distribution center in China, I've got a truly global business and find there is often something something somewhere that needs attention.
But I can walk away when necessary and take many 5 to 15 minute visits to the rest of my house and my family, as well as an hour walk most days. And I've always got a book going. So, I'm available and accessible most of the day, but I am not simply grinding it out the whole time.
Actual productive hours, average maybe 10. But it can be for 7 days a week at times. Just today 2 new hosting accounts, for instance. Not major projects, but they paid their money and expect results.