Early morning is the only way I can fit it in. When my kids were younger I would go out super early on the weekends so I could get a long ride in and still be home by a reasonable time. Like leave at 3-4 so I could be back by 9 or 10 kind of thing. My kids are older now so I don't have to leave as early on the weekends, but I still have to get up early to exercise during the work-week. My goal is 5-6 days a week, and I'm able to hit it most of the time. I'm also into randonneuring so I have to negotiate for a few pretty big chunks of time away from home during the warmer months, and I didn't do anything longer than a 600k until my youngest was in high school. If you want it bad enough you just find a way to fit it into your schedule. Can't wait until I retire, but that's still several years off for me.