My husband heads into work at 3am, returns about 7pm. He hasn't taken a vacation in over three years. He works seven days a week, and we alone are responsible for our retirement.
He does this all so I can be home fulltime with our daughters. They're not yet school age, but I am still teaching them now. And when school starts, I will have two full time jobs, mother and teacher. It's a harder way of life, but you do what's best for your children.
I typically work 9 AM to 3 AM. Same arrangement on the retirement. My last vacation was April 1999. I have a couple "breaks" to run one of my sons off to work at 8 AM. The other one goes to work at 11 PM. That nips 30 minutes out of my work day. My wife works from 9 PM to 7 AM. I take a late "lunch" at 3 PM with my wife.