With the Fall season now nearly halfway complete, the Daylight-Saving Time ritual of “falling back” in time has arrived. The time change will officially occur this Sunday, November 2, at 2:00am local time. Because the change in time, both morning and night, dictates when the sky is lit and when it is dark, sleep habits naturally come into play. Light and darkness are the most powerful timing cues for alertness and sleepiness in the human body.

As time passes in the 21st century, Daylight Saving Time is becoming increasingly controversial. In October 2023, the American Academy of Sleep Medicine (AASM) published an updated Daylight-Saving Time position statement.  The document was endorsed by 20 medical, scientific, and civic organizations. It held that the U.S. should eliminate seasonal time changes in favor of permanent Standard Time, which aligns best with human circadian biology.

Current evidence supports the distinct benefits of Standard Time for health and safety, while also underscoring the potential harm that results from seasonal time changes to and from Daylight Saving Time.

The concept of Daylight-Saving Time was first established in the U.S. by Congress after the Calder Act, or the Standard Time Act of 1918, was passed more than 100 years ago.

The legislation was more recently amended with the Energy Policy Act of 2005. The law changed the start and end dates of Daylight-Saving Time beginning in 2007. Clocks were set ahead one hour on the second Sunday of March instead of on the first Sunday of April. Clocks were set back one hour on the first Sunday of November rather than on the last Sunday of October. This had the net effect of slightly lengthening the duration of Daylight-Saving Time.