Put perhaps a little less harshly, what I mean is that if running is important to you (and I kinda think it should be), then your mind-set shifts from “Can I find the time for it?” to “When can I find the time for it?” You think in terms not of “Will I run today?” but “When will I run today?”
Because let’s face it, whether you run today matters to almost nobody else in the world but you. Your boss, the dog, traffic, errands, your kids, your friends, a little extra sleep—the list of claims on your time is endless. To wait to see if an opening magically arrives in your day when you’ll be able to run is to surrender your running to those claims on your time. And remember, almost none of those claims are going to care if you go to bed kicking yourself for missing a day of running. That’s not to say they’re evil or out to get you; they may very well love you. But they’re still almost always going to request that you do something other than change into your running gear and disappear for the next little while.
So if there are lots of claims on your time, anticipate when you’ll be able to run, and make it happen. During the work week, that will often mean getting a little less sleep and running early in the morning. So be it.