This month marks 100 years since daylight saving time was first used in the United States. The semiannual clock-tinkering ritual began in Europe two years earlier and eventually made its way across the pond as a way to save coal and energy during World War I.
Energy-saving discussions aside, what’s often lost in the daylight saving time debate is understanding how it affects the amount of daylight we see during our waking hours.
As cartographer and blogger Andy Woodruff aptly writes: “Usually the whining [about daylight saving time] is short-term shock at the sudden change in the timing of day and night, not a reasoned assessment of what it means for the timing of daylight over the whole year.”
What would happen if we ditched DST?
There’s a good case to be made for moving the clocks forward and keeping DST year-round (as many, me included, have argued before). But what would happen if we simply abolished DST and used standard time all year — like Arizona and Hawaii?
While the economic and public health effects would take a while to parse, the most immediate impact of scrapping DST would be a dramatic change to the sunrise and sunset schedule many of us take for granted.
Instead of summer sunsets after 8 p.m., it would suddenly get dark closer to 7 p.m. And those early June sunrises — when you begin to stir at 5 a.m. because it’s already getting light and you hear birds chirping at the crack of dawn — would be even earlier still.
The chart above shows many big cities in the United States would see their earliest sunrise well before 5 a.m. around the June summer solstice if we no longer used DST. Some places, such as Boston and Chicago, would see sunrise closer to the 4 o’clock hour — long before most people wake up in the morning. Perhaps William Willet, the British builder often considered the modern-day founder of daylight saving time, was on to something when he wrote “The Waste of Daylight” in 1907.
Critics of daylight saving time sometimes counter that summer days are longer to begin with, so there’s no point in shifting more daylight to the evening. But what about the spring and fall transition seasons in which the days aren’t quite as long?
This is where it’s useful to look at sunrise and sunset times over the course of a year if we ended DST.
In Washington, for example, year-round standard time would look like this.
Notice how getting rid of DST means sunrise would occur before 6 a.m. from late March until nearly October. Meanwhile, the first 7 p.m. sunset wouldn’t happen until May 1 (as opposed to early March, when we “spring forward”). By late September, it would already be getting dark before 6 p.m.
I imagine quite a few people would be unhappy with this kind of daylight schedule, which would leave us with much darker evenings for most of the year.
This leaves two alternatives: Either we keep the current system, or we adopt year-round DST.
Here’s what that would look like, again in Washington.
Under a year-round DST schedule, sunrise and sunset times would remain similar to what we’re used to, because we already observe DST for eight months of the year. However, from November to March, our mornings would be significantly darker. Sunrise in D.C. would be late as 8:27 a.m. in early January.
On the flip side, our earliest sunset of the year would be at 5:46 instead of 4:46 p.m. And even in January — America’s least favorite month of the year — the sun would still be up after 6 p.m. on all but the first few days of the month. Not bad, right?
Ultimately, if we had to choose between ditching daylight saving time, or keeping it year-round, the latter would be a lot more practical. Even Florida is trying to introduce year-round DST, though right now the proposal seems like a long shot. The daylight saving time debate makes headlines for a few days each year, but I’m skeptical that there’s enough political will to modify the system that has largely been used for decades (a few tweaks to DST start and end dates notwithstanding).
Yet if someday we do finally decide to pick one time and stick with it, let’s make sure it’s not year-round standard time.