On Tuesday, the US Senate lodged a rare unanimous vote on a bill that could have drastic technological and transportation implications: a permanent, year-round adherence to daylight saving time (DST).
The one-page "Sunshine Protection Act," as co-sponsored by Sens. Marc Rubio (R-Fla.) and Sheldon Whitehouse (D-R.I.), is now cleared for a vote in the House of Representatives after passing by unanimous consent in the Senate. This bill, as originally filed in 2018 and reintroduced in 2021, would reverse the Calder Act's introduction of a twice-a-year clock-change process in 1918, along with its eventual reinforcement by the Uniform Time Act of 1966.
The result would permanently leave clocks and timetables in the "spring forward" state of DST beginning in 2023, with the exception of states that had previously established specific time-change rules based on issues like different time zones in the same state. In terms of US politics, it's unclear whether either major American party will mount serious opposition in the House to its eventual vote there—and President Joe Biden has yet to announce his stance on the bill.
Why it started, what it does (and doesn’t) save
The US adopted DST after a wave of European nations, particularly Germany and Austria, embraced the practice in 1916 as a means of saving energy during World War I. But DST in the US was historically inconsistent even after the Uniform Time Act in 1966. Later laws updated the exact time frame when "standard" and "saving" time changes would occur.
In the decades since, populations around the world have debated the practice vociferously, and as recently as 2019, the European Union was on the verge of doing away with DST altogether, thanks to a successful vote in its Parliament. However, its original goal of ending DST in 2021 required collaboration by EU committees, which instead punted the time change process in favor of coronavirus reactions and the fallout of Brexit. If, when, or how the EU's vote in favor of dumping DST will play out are all unclear.
DST's original cited purpose, to conserve energy based on how much sunlight is available in a given season, hasn't proven as applicable to a modern, electricity-driven world, based on data gathered from energy companies in 2007 after the United States extended DST by three weeks. The US Department of Energy followed that up in 2008 with an estimate of 0.03 percent energy savings per year when DST was extended by three weeks.
Many studies have examined how car accidents would change should the United States freeze all clock changes, and a US National Institute of Health study in 2004 concluded that a permanent "spring forward" clock measure would result in a statistically significant reduction in deaths for both car passengers and bystander pedestrians.
Probably not another Y2K
When the US tweaked its DST calendar in 2007, the results didn't wreak Y2K-like havoc as some feared. But that change came in an era when both consumer- and enterprise-grade computers weren't as likely to have a permanent online connection—and thus get constant updates that range from security databases to full-blown OS updates. At the time, Ars reminded MacOS readers what hoops they might have to jump through to ensure that their systems would automatically update in line with the US's DST tweaks.
The 2007 shift is still a recent-enough footnote to reference when considering what changes may be needed to align the US's many calendar-based systems, particularly an internationally relevant tangle of transportation grids, to a permanent DST universe.
And then there's the scientifically based consideration of not losing up to a week per year adjusting our own biological clocks to align with a significant bump to our alarms, commutes, carpools to and from school, and much more. This arguably drives the loudest and most persistent protests from populations across the world to drop the practice once and for all.
This article has been updated to clarify a finding from a cited NIH study.
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