Round here, the village residents seem to get up at dawn, no matter what the actual time is. My friend-over-the-road is often up, dressed and out in her little car to deliver papers and get her produce ready for the fruit/vegetable round at about 4am in summer.
It's interesting to notice how ones body keeps to the 'usual' time. I was ready for bed at 9pm last night ('really' 10pm!) so I went. But as you say Mr Red, shift workers, night workers etc have their body clocks messed about and it has been proved this can cause serious medical problems.
Sister up in Scotland says after the clocks changed it now gets dark at around 3pm! I couldn't bear that.