The Reasons I Don’t Support Permanent Daylight Saving Time
At the moment, the House of Representatives has passed a bipartisan bill to make Daylight Saving Time permanent. Yeehaw, you think – finally we don’t have to switch the clocks anymore, and we’ll have more light all year long!
I wish it were that simple.
Unfortunately, Daylight Saving Time (DST) does not support the human body’s need for light in the morning and darkness at the end of the day. This duality is one of the lynchpins of healthy human physiology.
With permanent DST, we would have more darkness in the morning during the winter, when we need as much morning light as we can get, and more light at the end of the day in summer, when we need help winding down from long days of sunlight.
Ending the clock changes is the right call. Unfortunately, of the two choices, Permanent Daylight Saving Time is the one least compatible with human physiology.
I’ve long been an outspoken critic of changing the clocks twice a year – falling back in November and springing ahead in March.
With each switch, society experiences a type of jet lag that can manifest as depression in the fall and disrupted sleep in the days following the clock adjustment in March.
Currently, we live under eight months of Daylight Saving Time, which means that when we set the clock ahead in spring, we lose an hour of morning light.
The sun doesn’t move – only the label on the clock does.
Whichever direction you move the clock, someone’s morning or evening light exposure changes.
Why Morning Light Matters
The first map below shows how many winter mornings the sun would rise after 8:00 AM under permanent Daylight Saving Time.
Where I live in Oregon, that’s 90 days of darkness at 8:00 AM!
The second map shows morning light under permanent Standard Time. Where I live, there would be zero winter mornings with the sun rising after 8:00 AM.
This varies depending on how far north you live, but compared with the permanent DST map, the difference is compelling.
Think about what permanent Daylight Saving Time would mean for many families with children: waking up in the dark, walking to the bus stop in the dark, and starting school… in the dark. Most U.S. schools start at or before 8:00 AM, and some considerably earlier. This is why permanent Standard Time is endorsed by sleep medicine organizations, child safety organizations, even the National PTA.
Your Move
Visit savestandardtime.com and look up the maps for your own state.
It’s not an advocacy blog – it’s built on the research of circadian biologists and sleep medicine specialists, whose position is endorsed by professional and scientific bodies including the American Academy of Sleep Medicine, the Sleep Research Society, and the National Sleep Foundation.
Warmly,
Dr. Krista
Olive Says
What’s a clock and does it have anything to do with when I get fed?
If not, uninterested.