This weekend millions of Americans performed a ritual that feels oddly modern and strangely primitive: we change the clocks.

At 2:00 a.m. Sunday morning, the nation “sprang forward,” losing an hour of sleep in the name of daylight saving time. The practice feels harmless, even quaint. But modern circadian science is increasingly clear: this simple act of moving the clock may be quietly harming our health.

And if we listen carefully, Jewish tradition may have been warning us about this kind of disruption for centuries.

The Body Has Its Own Clock

Human beings do not run on mechanical time.

We run on biological time.

Deep within the brain sits the suprachiasmatic nucleus (SCN), a cluster of neurons that functions as the body’s master clock. This circadian system regulates sleep, hormones, metabolism, mood, and cardiovascular function, all synchronized primarily by the rising and setting of the sun.

When we abruptly shift the clock by an hour, the body cannot instantly follow. The result is circadian misalignment, a biological state similar to mild jet lag.

And the consequences are not trivial.

Research has repeatedly shown measurable health effects in the days following the spring transition to daylight saving time. Studies have documented increases in heart attacks, strokes, hospital visits, and fatal traffic accidents in the days immediately after the clock change.

One large analysis found heart attacks rise significantly on the Monday after the spring shift, while stroke risk also increases in the days following the change.

Even beyond these acute effects, circadian disruption is associated with depression, metabolic problems, and long-term cardiovascular risk.

In other words, changing the clock is not just inconvenient.

It is biologically destabilizing.

Recent modeling research from Stanford even suggests that ending daylight saving time in favor of permanent standard time could prevent hundreds of thousands of strokes and millions of cases of obesity in the United States.

As a sleep psychologist, none of this surprises me. The body is exquisitely sensitive to time cues, especially morning light. When we shift the clock, we are essentially forcing millions of people to wake up in biological darkness.

It is the circadian equivalent of social jet lag.

Judaism Runs on Solar Time

Jewish life has always been organized around natural time.

Long before wristwatches or digital clocks, Jewish law structured daily life around sunrise, sunset, and the cycles of light and darkness.

Morning prayer begins after dawn. The Shema is recited before sunrise. Shabbat begins at sunset.

The sacred calendar itself follows the moon.

Judaism, in other words, has always respected the rhythms of the natural world.

This is not accidental.

The Torah’s very first act of creation is the separation of light and darkness, establishing time itself:

“There was evening and there was morning.” (Genesis 1:5)

Even the mystical tradition understood that human beings are meant to live in harmony with cosmic rhythms.

A Kabbalistic Insight About Time

In Kabbalah, time is not just mechanical measurement.

It is spiritual flow.

The Zohar describes divine energy moving through the day like currents through a river. Different hours carry different qualities of consciousness and spiritual potential.

Morning light is associated with chesed, expansive kindness. Night is associated with introspection and hiddenness.

When we artificially manipulate time, we are not merely adjusting schedules.

We are interfering with the natural choreography between body, soul, and world.

Circadian biology now tells us something remarkably similar: our physiology evolved to synchronize with the rising sun.

Light in the morning anchors the brain’s clock.

When morning light disappears, as it does during daylight saving time, the body struggles to recalibrate.

A Chasidic Story About Time

There is a story told about Rabbi Levi Yitzchak of Berditchev.

One morning, a student noticed the rebbe gazing out the window at sunrise.

“Rebbe,” the student asked, “why do you watch the sunrise every day?”

“Because the world is being renewed again. And I want to greet it properly.”

The story is simple, but its message is profound.

Every morning, the rising sun resets the rhythm of life.

Circadian scientists would say something similar today: morning light is the most powerful signal for regulating the body’s clock.

It tells every cell in the body: the day has begun.

Daylight saving time does the opposite.

It hides the sunrise.

The Jewish Case Against Daylight Saving Time

There is something ironic about a modern society that prides itself on technological mastery yet cannot respect the simplest biological truth:

Human beings are creatures of light and darkness.

For Jews, this insight is deeply embedded in our tradition.

Our prayers follow the sun.

Our holidays follow the moon.

Shabbat itself begins not when the clock says so, but when the sky changes color.

Perhaps the most Jewish response to daylight saving time is the simplest one:

Let’s stop pretending we control time.

Let the Sun Set the Clock

Medical organizations, sleep researchers, and chronobiologists are increasingly aligned on a recommendation: if governments must choose a permanent time system, standard time is healthier than daylight saving time, because it keeps mornings brighter and better aligned with human circadian biology.

Ending the twice-yearly clock change would not solve every sleep problem.

But it would remove a needless biological stressor affecting millions of people.

And perhaps it would remind us of something older and wiser.

The Jewish calendar never tried to control the sun.

It simply learned to live with it.

In an age of artificial light and digital clocks, that ancient humility may turn out to be the most modern health advice of all.

© The Times of Israel (Blogs)