Dood, back in the 80s & 90s when I was a hard core cyclist, I'd be up every weekday just before dawn for a 20-25 mile training before going to work. And Saturdays I'd head out at dawn for a "century" with friends and still be home for lunch. Now I walk instead. So I like to get in 3 miles as early as possible. Of course, the later sunset does make it easier to do my after dinner 3-miler. In fact, in summer, I can push the walk to as late as 9PM when it's still light, but definitely cooler.