If you are in a position where you do what you love to do for a living, time doesn't really matter that much. In this case your work is your hobby and you wouldn't know how to use your time any better anyway. As long as that position provides sufficient financial means you are in a great position to achieve personal and professional satisfaction. Alas, for many people that is not the case. They might love what they do but they don't want to do it 24/7/365! I am in this category and I think that is fine!
If you are also one of these people then you should ensure that you balance your time between work and home effectively. Notice that this is not just a saying that you use to show your boss how dedicated you are but something important for your longterm health and well being as well as your effectiveness at work. To be successful also means to know when to say "No". Take care of yourself and actively schedule time to recharge your batteries! Note that in some cases the work just needs to get done and you have to suck it up and do whatever needs to be done, whenever it needs to be done. But that should not be your default.
