I posted this in another thread but I thought it might be interesting to other readers. In 2013, Strava took a random northern-hemisphere Saturday and created a heat map of all the rides. You can see it here or read the blog post about it. By observation, the slider is local time. So if you put the slider at 8am, it shows you all the riders who were out at 8am local time. And that's kind of interesting. The brightest country on the map seems to be Britain. By a mile. I'm sure it is indicative of strava usage and possibly mobile phone ownership and mamil-population, and nothing deeper - but I find it interesting nevertheless.