Most of us typically wedge in hobby time sometime after dinner and on weekends when possible, but occasionally I can steal some time from the wee small hours of the morning. When I was bike racing, I'd typically wake up a bit after 5am to train and I still occasionally see that time of day now that I'm, um, "retired" from racing. But not often.
An exception to my general rule of "sleeping in" (heh, til 6:30) occurred one recent morning. I'd woken up at my old usual time, and was - inexplicably - wide awake. The responsible thing to do (health-wise) would have been to get out on my bike, or at least go for a run. But the responsible - or at least much more fun - thing to do, was to go down in the basement. And not to get on the treadmill or trainer.
I took advantage of the "found" hour to glue down some track at the Saybrook Wye and lay some roadbed "north to Essex" (on the liftout).
I've seen folks using cans of soup and vegetables to hold their track down. You can use bottled water as well.
Tacking down the roadbed to Essex.
I've written before how important it is to have little projects ready and available to tackle so you can always make some progress on your layout, no matter how incremental or small an amount of time you have available. And sometimes you can do one of these simple projects during some time you've stolen from other things (like sleep, apparently).