Why the Summer Solstice May Be the Happiest Day of the Year

Why the Summer Solstice May Be the Happiest Day of the Year

The summer solstice is June 20, the longest day of the year in the Northern Hemisphere. But do the extra hours of sunshine make you happier?

In general, people are more cheerful in the summertime, according to Philip Gehrman, associate director of the Behavioral Sleep Medicine Program at the University of Pennsylvania. Light serves as the strongest cue to regulate circadian rhythms, which include the sleep cycle, hormonal fluctuations and body temperature and follow a roughly 24-hour pattern.

View the full story in TIME

This story was also featured in Yahoo! News and Fortune