Longer daylight hours make driving safer, lowers car accident rates, and lowers the risk of pedestrians being hit by a car. For example, robberies drop about 7% overall, and 27% in the evening hours after the spring time change. Daylight in the evening makes it safer for joggers, people walking dogs after work. Also is safer for children playing outside, for example.
On the other hand, changing sleep patterns, even by one hour, goes against a person’s natural circadian rhythms. This thing has negative consequences for health. One study found that the risk of a heart attack increases 10% the Monday and Tuesday following the spring time change. Researchers found an increase in cluster headaches (sudden and debilitating headaches) after the fall time change, as well.
Later daylight means more people shopping after work, increasing retail sales. Also more people driving, increasing gas and snacks sales for eight months of the year.
On the other hand, the Monday after the spring time change is called “Sleepy Monday”. That’s because it is one of the most sleep-deprived day of the year.
When the day is lighter later, people tend to participate in more outdoor activities after work.
But the simple act of changing clocks costs Americans $1.7 billion in lost opportunity. This cos ist based on average hourly wages. This means that the ten or so minutes spent moving clocks, watches, and devices forward and backward could be spent on something more productive.
Approximately 1.5 billion people in 70 countries observe DST worldwide. In the US, 48 states participate in Daylight Saving Time.