> I think it has to do with temperatures. More likely shorter days as you go further North. If you slept at lunchtime until 14:30 there would be less than two

> I think it has to do with temperatures. More likely shorter days as you go further North. If you slept at lunchtime until 14:30 there would be less than two hours of usable daylight left during December and January. [Edit] - This for the latitude of Southern England.