In the summer in Boston, the shortest night gets down to under nine hours, whereas winter nights are upwards of fifteen hours.
If we were alive before blackout shades and sleep masks, the duration of evening would effect our sleeping patterns, no?
During the winter, you might go to bed early because the sun sets early, plus it's cold and you'd want to get under a blanket with your warm cave-mate. In the summer, you'd stay awake longer with the longer days, and the rising sun would wake you up after a slumber of perhaps under eight hours.
So dual questions here:
- Would we naturally sleep longer in the winter (maybe even much much longer, judging by sunset/sunrise patterns!)
- Would we sleep under eight hours during part of the summer, because of sunlight hitting our eyelids?
Sleep hygiene be damned! I don't think that uniform bedtimes match naturally ebbing and flowing sunrises/sunsets, although they certainly do match modern work schedules :(