Like any other year, Daylight Saving Time will end on the first Sunday of November. The clock moves back by an hour, repeating the lap between 1 am and 2 am. For some people, this is good news, as we get an extra hour that night. But for many, changing the clock disrupts daily rhythms, prompting calls to eliminate Daylight Saving Time. A 2020 poll conducted by the American Academy of Sleep Medicine indicates that 63% of Americans support a national, year-round permanent time zone. Legislators in dozens of states have introduced bills to abolish Daylight Saving. Despite the usual biannual disgruntlement over the clock change, most bills have been rejected or stalled because stakeholders cannot agree on what time we should land on.
Year-Round Standard Time versus Daylight Saving Time
Public debate over daylight saving time largely centers on the nuisance of changing the clock. Most people can do without a mini jetlag twice a year. But what would life look like if we stayed in one time year-round? Let’s show a typical summer and winter day in Standard versus Daylight Saving time, taking New York’s latitude as an example. Staying year-round in Standard Time means that nothing changes in the winter (when we are already on Standard Time). On December 21, the shortest day of the year, the sun rises at 7:17 am and sets at 4:32 pm in New York. In summer, however, we now stick with Standard Time. On June 21, the longest day of the year, the sunrise will be at 4:25 am and sunset at 7:31 pm.
Now, let’s say we make Daylight Saving Time our permanent clock, keeping the time we are currently on in summer. On the winter solstice, the sun will then rise at 8:17 am and sets at 5:32 pm. We keep our typical summer solstice – on the longest day of the year, the sun rises at 5:25 am and sets at 8:31 pm. If these numbers are dazzling you, here is what it comes down to. With permanent Daylight Saving Time, daylight starts and ends later. This is great in the summer, when we want long evenings and its already light in the morning anyway, but depressing in the winter, when it is dark when we go to work. With permanent Standard Time, the day starts and ends earlier. This prevents dark winter mornings, but it also means the sun rises very early in the summer, while it gets dark an hour earlier than we are used to in the evening.
The Gains of No More Clock Changes
The main benefit of a permanent year-round time is eliminating the disadvantages of clock changes. Clock changes cause sleep deprivation in both the fall and the spring, though the impact is greater when the clock springs forward. A study published in Sleep Medicine Reviews confirms that employees lose about 40 to 60 minutes of sleep each night in the week after Daylight Saving Time starts. According to Yvonne Harrison, senior lecturer at Liverpool John Moores University, sleep is disrupted around the fall change as well. People wake up earlier and wake more often through the night. The cumulative effects over at least five days result in a noticeable sleep loss.
Sleep deprivation due to the clock change poses significant risks and costs for employees and organizations, including increased workplace injuries and accidents, lower work engagement, increased slacking behavior, and flawed decision-making. Removing the clock change also eliminates minor pragmatic hassles, such as confusion around scheduling meetings in the week of the time change or manually changing clocks. And those who don’t pay attention during the weekend of the change, don’t show up an hour early at work, or too late, on the Monday after.
The Battle Between Body Clocks and Social Clocks
While a majority of Americans agree that we should rid ourselves of the clock change, deciding which time to make permanent is more difficult. Sleep and health scientists strongly advocate for sticking with Standard Time. Their arguments rest on the alignment between the body clock and the sun clock. Our circadian rhythms are based on daylight. Our body knows when to make cortisol to spring into action in the morning and when to make melatonin to prepare our body for sleep, based on our exposure to daylight. In Standard Time, the body is in its natural biorhythm that follows the sun, preventing biological processes from being disturbed. Staying in this natural rhythm has significant benefits for health, because these rhythms direct our cells, muscles, and organs.
So why don’t we just go with Standard Time? Because we also have a social clock. This social clock determines when coordinated social activities and events happen. For instance, regular business hours are 9 am to 5 pm, regardless of when the sun rises or sets. If we follow our biorhythm, we should wake much earlier in the summer — maybe as early as 5 am — but for most people, work doesn’t start until 8:30 or 9 am. The social clock fits better with Daylight Saving Time, in which the day begins a bit later, but has a longer evening. Businesses therefore favor Daylight Saving Time because people are more likely to shop, attend sporting events, or engage in other recreational activities when it is still light in the evening.
Making the Best of the Time Change
As long as we can’t agree on time, we are likely stuck with resetting the clock twice a year. There are strategies to make this change more palatable. How you fare next week also depends on your chronotype. If you are a night owl, you might not even give the time change much thought. Going to bed and getting up later aligns with your body’s preferred rhythm. If you are an early bird, however, the time change might sting, as your body won’t let you sleep in. The trick is to go to bed early. You then likely wake up early, but you can make the most of this extra hour by getting a head start on work, exercising, relaxing, or spending some quality time with kids, as they, too, are most likely up already.