Hi Paulette,
I try most days (M-F) to only work 9-5. Some days I stay up later if I'm really excited about a project or really need to finish something. But other than that, I try to stick to 9-5 because I don't want to burn out.
One thing that really helps me is to make a list of things I need to do the next day. Then I don't feel like I need to stay up until 10pm doing stuff, because I know I will work on it tomorrow.
Also, if you find you really need to work 14 hr days all week, you may want to trim down the amount of projects you're working on. Last year, during November, I was exhausted because I was working on a big illustration project, a tree for the Festival of Trees, inventory for a BIG art festival, and a few other projects! In addition to teaching painting classes!
It completely burned me out, and after that I decided to limit myself to only about 3 projects at a time. If ideas or other stuff come up, I write it down so that I can work on it at a later date. But I definitely find myself much more focused, and I do a much better job, when I limit the number of projects I work on.