WE’VE TINKERED WITH TIME FOR MORE THAN 100 YEARS

For more than a century, we, as a country, have tinkered with time. The Standard Time Act of 1918 established standard time zones and daylight saving time. It was intended, at least in part, to help the nation save energy in a time of war, though there’s not much evidence that it succeeded.

In different forms, daylight saving time has persisted ever since, primarily as the biannual ritual of turning the clock ahead one hour in the spring and one hour back in the fall. Advocates laud longer, lingering evenings, which supposedly promote tourism and outdoor activities.

They say daylight saving time is good for you and the nation. They are wrong.

In 2020, the American Academy of Sleep Medicine, a professional society of physicians and researchers who treat and study sleep disorders, published an official position statement on daylight saving time. Bottom line: It argued for abolition of daylight saving time in favor of a fixed, national standard time year-round. The Society for Research on Biological Rhythms agreed.

There are a lot of reasons why daylight saving time was and is a bad idea beyond the fact it never really fulfilled its original, intended purpose, and that its declared benefits are minimal and debatable.

The biggest knock against daylight saving time is, fundamentally, that it’s bad for our health.

Biology helps explain why: Most living organisms, including humans, are governed by circadian rhythms — a 24-hour cycle that dictates physical, mental and behavioral changes throughout the day and night. There are many biological clocks within our bodies, from our brain, which hosts the master clock, all the way down to the level of cells, which direct periods of activity, from when we eat and

sleep to the release of hormones and regulation of body temperature.

Our clocks are calibrated with the rising sun, reset each morning to match the environmental clock. Simply put, life switches on with the dawn. But this one-hour change in clock time to daylight saving time leads to less exposure to morning sunlight, and our internal biological clock needs to be exposed to morning sunlight to adjust to local time.

When exposure to morning sunlight is reduced, our biological clocks will drift later and later, making it harder to wake up. The one-hour shift in clock time during daylight saving time also exposes us to more evening light, which further pushes the biological clock to a later time and makes it more difficult to fall asleep.

Because of the effects of reduced morning light and increased evening light on our biological clock, daylight saving time leads to sleep loss and a mismatch between the body clock and local time (also called social jet lag). Both sleep deprivation and social jet lag have negative effects on physical and mental health, including increased risks for diabetes, obesity, heart disease, depression and some forms of cancer.

Keeping daylight saving time during summer or year-round has serious implications for public health and safety. The problem is exacerbated in different time zones. Because of the sun’s movement, exposure to sunlight differs between the eastern and western edges of each time zone, with the latter receiving less exposure and daylight saving time creating further misalignment.

Health data shows that people living on the western edges of time zones (like San Diego) get approximately 19 minutes less sleep every night than people on the eastern edges — with resulting higher rates of related health problems.

These negative effects can be prevented by simply not switching to daylight saving time. That is why biological rhythm and sleep experts recommend permanent standard time, which most closely matches with sun and social clocks, throughout the year. Two states already do so — Arizona and Hawaii — with at least 19 others having passed or enacted legislation to follow suit, if Congress allows.

In 2018, nearly 60 percent of California voters approved a proposition to end biannual clock-changing, consistent with federal law.

So far that effort has gone nowhere. We need to act. Then we can sleep on it, happier and healthier.