Every year, twice a year, in most of the United States, Americans are forced to switch their clocks back and forth an hour due to the strange ritual known as Daylight Saving Time, or DST.
And every year, twice a year, the clock-changing ritual of DST has been shown to have a detrimental effect on Americans across the country. As of March 11, clocks moved an hour forward, pushing sunrise and sunset a little later, and meaning until days start getting longer toward the summertime, we'll all be spending more time in the dark.
But while blaming DST is common for various issues, such as Seasonal Affective Disorder (SAD), Circadian rhythms expert and engineer Willem Sillevis Smitt, a senior director of strategic marketing at Lumileds, said people can avoid these problems by adjusting the brightness and colors of the artificial lights they expose themselves to in the evening.
"When I look at how people report the impact of daylight saving, it mostly impacts how people sleep," said Smitt, an expert in "human-centric" lighting. "Most of us go to bed way after 7 p.m., when it's already dark. So my conclusion was that the impact must come not so much from sunset and sunrise, but more from how we keep the lights on in the evening."
To help ease into the evening, Smitt recommends making sure the lights are warm and dimming the lights a bit as darkness falls.
"A lot of it is about common sense," he said. "The best thing you can do with light during the day is, if it's a bright and sunny day and the weather allows it, go outside for 10 to 20 minutes. It will actually help you get to sleep at night."
To help consumers make the adjustment, Lumileds develops lights that automatically dim based on the time of day, and shift from a starker, blue light during daytime to a softer, orange light at night.
"Human beings evolved with very bright light levels during the day and very dark levels at night. ... If it's a nice day, we're under the blue sky. How we evolved during the night, if there was any light, it tended to be fire," Smitt said. "The technology that we developed has the ability to have a different color during the day and during the night, to match this light pattern that we evolved with."
It's the same principle behind the iPhone's "Night Shift" feature that adjusts light based on the time of day, to help prevent users from giving themselves insomnia by staring at a bright white screen late into the night.
But beyond just color, Smitt said Lumileds technology is optimized to spectral output that best resembles natural light and has the most beneficial effect on human test subjects.
"In the evening, you want to limit and especially wind down the light levels as the melatonin [the natural hormone associated with sleep onset] starts to come up a little bit," he said. "This is why winding down is so important if you want to have a good night's sleep, [which] really helps to feel good, to be active, and have a good mood."
Origins of a ritual
Daylight Saving Time (DST) was officially enacted nationwide in 1966, purportedly to give farmers extra hours of daylight, although many pointed out that farmers just wake up when the sun rises.
In fact, in Indiana, agricultural regions refuse to participate, precisely because DST makes farmers' lives harder. And the great states of Arizona and Hawaii permanently refuse to acknowledge DST.
Massachusetts recently convened a state commission to investigate the idea of ending DST, which found there would be "positive benefits" with making the November clock-change permanent, but only if other states made the same change simultaneously, to prevent interstate confusion.
As of 2018, there are dozens of petitions on Change.org to end DST. The Standard Time movement says DST is causing chaos and must be ended. Organizers with the #LockTheClock movement urge anyone with anti-DST leanings to contact their state and local legislators.