It's very hard with a full-time job, family and 3 kids. I treat it like how busy parents treat going to the gym. You have 2 options really.

1 - Wait until they go to sleep. Usually 10pm. Con: Most of the time you are really tired by then. Most likely won't happen.

2 - Wake up really early. 5am.

Doing either of these means you need to sacrifice entertainment. I rarely have time for TV or video games anymore. Be warned single devs!