HANSCOM AIR FORCE BASE, Mass. -- Daylight saving time begins the second Sunday in March and ends the first Sunday in November, when clocks are adjusted one hour back to standard time.
Congress instituted daylight savings time during World War I and again during World War II, and once again during the energy crisis of the early 1970s. The idea was that having an extra hour of light later in the afternoon would save energy by decreasing the need for electric lighting.
After World War II, it was left to state governments to set the start and end dates for saving time. Because this created many railroad scheduling and safety problems, Congress passed the Uniform Time Act of 1966 standardizing time zones and daylight-saving practices across the United States. The Uniform Time Act allowed states to pass laws exempting themselves. The only states that don’t observe daylight saving time are Hawaii and Arizona with exception to the Navajo Nation. It’s also not observed by these U.S. territories: American Samoa, Guam, Puerto Rico and the Virgin Islands.
During the spring-forward, fall back shift, our body needs time to readjust to the new light/dark cycle, so it can be hard on the body and hard on sleep. This cycle, known as the circadian rhythm, is a fine-tuned system that our bodies use to regulate time. "Falling Back" - going from daylight savings times to standard time each November is easier than losing sleep when Daylight Savings begins. Even though springing forward is harder on the body, turning back in November still affects the circadian rhythm, and there is less daylight at the end of the day which adds extra caution especially when driving where pedestrians are present.
According to the Defense Logistics Agency Installation Management, fire officials use "Fall-back" time to remind employees to change batteries in smoke detectors and other home safety devices.
The National Fire Alarm and Signaling Code requires that a working smoke detector be installed in and outside every room used for sleeping, as well as on every level of the home including the basement. Homes that use wood or natural gas for fuel should also have at least one carbon monoxide detector.