I work for myself as a "freelancer" in the television business. Thus, I work different hours every week. The longest stretch I did was 28 days straight a couple years ago. I'd just broken up with a gal, so it was the perfect thing at the time.
Some days, I'll work for one client from 8:00 am until 4:00pm, then go over to Comcast and technical direct their newscasts until nearly 2:00 am the next day. Do that a few days in a row and you're pretty well spent! But when you work for yourself, you take the work when it comes because there may be a week here and there where you've only got two or three days of work!
As for vacation, I just took a week in CO. First vacation in about 2 1/2 years.
It's turned out well for me since going out on my own four years ago. It took two years to double what I'd been making in salary after eight devoted years to a network that eventually went under and even stopped payment on my last paycheck!
I still have it as a momento....