The American Academy of Sleep Medicine has come out with its first-ever position statement on the biannual switch between Standard Time and Daylight Savings Time. The verdict: America should ditch the switch and stick with one time year-round. The current system of setting clocks an hour ahead in the spring and an hour back in the fall — a relic of World War I — messes with peoples’ sleep habits twice a year in ways that may be longer-lasting than previously thought, and can even pose societal health and safety dangers. It might be time to set the clocks once, and leave them there.
The academy comes down on the side of using Standard Time as the year-round system. That issue requires more debate, as it would mean permanently giving up those longer hours of evening sunlight in the summer for physiological benefits that the academy itself admits aren’t strongly in evidence. Less debatable is the argument that the process of changing the time by an hour twice a year is disruptive to both human health and societal functioning.
In America as in most of the world, we “spring forward” and “fall back” by one hour twice a year to give ourselves sunlight later in the day during the summer. But it means losing an hour of morning sleep every March. The effects of that “social jet lag,” the academy paper concludes, can aggravate an existing “sleep debt” with results like increased cardiovascular problems and even car accidents. While the return to Standard Time in the fall feels like the gift of an extra morning hour, that transition, too, has been “associated with sleep disruption, mood disturbances and suicide,” states the academy.
While just two states currently opt out of the national dual time system (Arizona and Hawaii, both on Standard Time), more than 30 others are considering it. That threatens a national patchwork of not just two time systems but three: Standard Time, Daylight Savings Time, or both. The mere proposal in Illinois earlier this year to take the state permanently to Daylight Savings Time had Metro East businesses and residents fretting about how it would complicate life on the border with St. Louis. As this newspaper said then, this is an issue that should be decided by Congress, not state legislatures.
The academy recommends universal Standard Time because, it argues, those lighter mornings and darker evenings may work better with natural human sleep cycles. But the academy admits “little direct evidence” exists that it makes a physiological difference which system is used, and that the greater problem is the biannual disruption. Other experts point to things like lower crime rates during Daylight Savings Time (because darkness falls later). Either way, it appears, Americans would benefit from one nationwide system.
St. Louis Post-Dispatch