Starting at work before 10 a.m. is not tantamount to torture. According to the lecture slideshow, a rat living in total darkness has shifting waking period. Circadian rhythm is reset through external cues such as sunlight and temperature. This suggests that people tend to wake latter during the winter, but earlier during the summer. Start times should take sunrise into account. According to 10 Things You Should Know about Sleep, bright light helps reduce melatonin levels. Because the sun rises long before 10 a.m., a 9 a.m. start time is very reasonable. The slideshow states that adolescents tend to stay up later, but adults can be either morning or evening people depending on genetics. Instead of forcing people to start work at the same time,
