Although we dutifully adjust our lives for it twice a year, the whole “Spring forward, fall back” phenomenon can be puzzling. For many people, every time the clock change approaches in spring or fall, it brings with it at least a moment of confusion: How does daylight savings time work, again? What day do we do this, and what time exactly do we change our clocks? Are we gaining an hour, or losing one? If that hour is truly lost, where does it go? And is it Daylight Saving or Daylight Savings Time?
That last one is easy: Strange as it sounds if you’re used to saying the “s,” the proper name is Daylight Saving Time. As for the rest of it, here are the facts you need to know about springing forward and falling back.
Why Does Daylight Saving Time Exist?
The first person known to have suggested a seasonal adjustment of time was none other than Benjamin Franklin, who noted in 1784 that sleeping in despite the sun’s rising earlier in the summer was a waste of good daylight. He suggested, humorously, not a nationwide changing of clocks but rather a volley of early morning cannon fire to rouse people from their beds. Several other innovators around the world had similar ideas over the next century, and some proposed more serious plans to do something about it, but ultimately these were seen as impractical and unwelcome.
It was World War I and the urgent need to conserve fuel that finally made 31 nations implement a version of Daylight Saving Time, or DST. After the war was over, most of them returned to “normal,” but soon enough World War II began, and 52 countries adopted the energy-saving schedule adjustment. Some changed their clocks for the whole year, including the United States. The U.S. remained on what was then called “wartime” from 1942 to 1945. (Daylight Savings Time would be extended again during the oil crisis of the 1970s.) After the war, when mandatory nationwide “wartime” ended, clock-related matters were left to state and local governments to regulate (or not) as they chose.
The federal government didn’t attempt to standardize the process again until 1966, when the Uniform Time Act established dates and times for those areas choosing to change their clocks. Further adjustments were made in 1986 and 2007, and today most people in the U.S. change their clocks at the agreed-upon time and date twice a year.
There are exceptions, however. The U.S. territories of Puerto Rico, Guam, American Samoa, the U.S. Virgin Islands, and the Northern Mariana Islands do not observe daylight saving time, nor does the state of Hawaii. In the lower 48, only Arizona does not use DST, although the Navajo Nation, located within Arizona, does, while the Hopi Reservation, located within the Navajo Nation, does not. (Indiana mandated Daylight Savings Time observance in 2006; before that, some counties in the state changed their clocks while the others didn’t, compounding the confusion in a state spread across two time zones.)
Canada and Mexico change their clocks along with the U.S., although there are some regional exceptions and slight differences in Daylight Savings Time start and end dates. Much of the European Union uses Daylight Saving Time, for now—there is talk of abandoning the practice, as some European countries not in the EU, and Russia, have already done. In the Southern Hemisphere, countries that practice Daylight Savings Time spring back and fall forward, and most Asian and African nations do not use Daylight Savings Time at all.
How Does Daylight Savings Work? Are We Gaining or Losing an Hour?
Twice a year, most people find themselves wondering, how does daylight savings work? In the spring, we “spring forward,” moving our clocks ahead one hour so that 1:59 a.m. turns not to 2 a.m. as usual but to 3 a.m., skipping—or losing—an hour. Most people don’t think about it, as they are asleep, but this spring day is only 23 hours long.
In the fall, when we “fall back,” the clocks go from 1:59 a.m. back to 1 a.m. instead of to the usual 2 a.m., repeating—or gaining—an hour. This fall day is 25 hours long, and the hour between 1 a.m. and 2 a.m. repeats. That means if a baby is born at, say, 1:45 a.m.—or if for some reason you’re awake and have something scheduled at that time—it’s important to specify at which 1:45 a.m. the birth or event is taking place.
How Does Daylight Savings Time Work?
Of course, Daylight Saving Time does not have any effect on the sun or the changing of the seasons. It simply alters the way we experience those aspects of nature through our clocks and calendars. By shifting those points in the day when we’ve decided it’s time to get up, to work, and to eat dinner, we can have slightly more daylight hours toward the end of our days for nearly eight months out of the year. When it comes to how does daylight savings time work, the simplest facts are:
Daylight Saving Time in the United States begins at 2 a.m. on the second Sunday in March and ends at 2 a.m. on the first Sunday in November.
These days, most clocks change on their own, but we still need to pay attention to those that don’t, like old-fashioned alarm clocks, watches, and the digital clocks in cars and on stoves.
What Are the Pros and Cons of Daylight Saving Time?
Daylight Saving Time feels entrenched in our society, but it is not without controversy, and it is not a given. As mentioned above, countries have been known to give it up entirely, even decades after implementing it, and more are likely to follow, as further research evaluates the benefits and drawbacks of this regular hiccup in our schedules.
Historically, advocates for Daylight Savings Time have said it saves energy because, with more daylight, people use less electricity to light their homes and spend less time inside running appliances. It also has been praised as a method of reducing traffic accidents and crime: When it’s lighter later, the reasoning goes, we spend less time commuting in the dark and hanging around outdoors in the dim light preferred by criminals.
Other celebrated aspects of Daylight Savings Time range from the wholesome (it gives children more time to play outside) to the financial (it gives adults more time to shop, and makes more money for sports and recreation industries, where an extra hour of daylight can translate into many millions of extra dollars.)
Opponents of Daylight Savings Time claim that the practice may not save much energy after all, and may even increase the use of electricity in some cases. Similarly, they say Daylight Savings Time might not actually lead to an overall improvement in public safety, and that sleep-deprived workers and drivers are more likely to make deadly mistakes.
Detractors also claim that adjusting to the time change interrupts our natural cycles of sleep, leading to fatigue, a greater susceptibility to illness, and even a brief increase in heart attacks. Interestingly, despite the common belief that DST was instituted to benefit farmers, the agriculture industry fought against the switch when it was first introduced (having to adjust to the clock, rather than work with the sun as usual, disrupted their routines with detrimental effects) and many farmers still oppose it today.
Although many supposed perks and drawbacks of Daylight Savings Time are contested, no one disputes that time changes can be confusing—and not just in the sense that they might make you late for a morning meeting. In 1922, President Warren G. Harding issued an executive order mandating an earlier start for federal workers, while letting other employers in D.C. decide whether to join in. This effectively turned Washington into a city with no set schedule, and the resulting chaos was so overwhelming that Harding was forced to repeal his order.
Even today, there are aspects of life that can’t easily be made to fit neatly into our manipulation of the clock. Amtrak trains running on the two nights of the year when Daylight Savings Time begins and ends must either stop and wait for an hour or speed up and attempt to make up for lost time.And we can only guess what Benjamin Franklin would have thought of the headaches his idea now causes for airlines trying to schedule international flights among nearly 200 countries in different hemispheres, each with a quirky clock-changing system of its own.
What Else Should I Do When I Change My Clocks?
You’re probably familiar with the idea of changing the batteries in your smoke detectors every time you change your clocks. The International Association of Fire Chiefs has been advocating tying this life-saving task to that other twice-yearly chore for the past 30 years. It works because announcements about turning clocks forward or back are nearly unavoidable and, even if you do manage to miss the reminders, you’ll certainly notice the next day when your phones and computers have automatically adjusted themselves.
The time change is a good opportunity to attend to other household tasks that are best done twice a year. So what else might you link to your Daylight Savings Time fall and spring routines?
- Along with smoke alarms, change the batteries in carbon monoxide detectors and any other safety monitors in your house.
- Flip your mattresses and wash your pillows.
- Check your home and auto emergency kits to make sure you’re prepared for a storm or power outage.
- Replace air filters to help ensure heating and air conditioning systems are running efficiently.
- Declutter your bathroom and kitchen and get rid of expired food, products, and medicines.
- Deep clean anything that doesn’t get cleaned as part of your regular routine, like the oven.
And—while you’re at it—use these biannual blips in the passage of time as reminders to take care of anything else that’s important to you. Even if the adjustment is difficult for you, you can take a moment to be thankful that at least you’re not being awakened by the blast of a cannon.