The Mortality Cost of Daylight Saving Time

Disclaimer: I am an actuary. ASA designation pending (expected June or July 2026). The thoughts and analyses here are my own explorations, not professional advice. Draw your own conclusions.

I am building a circadian rhythm app. One-line pitch: it pre-shifts your schedule and light exposure leading up to the spring daylight saving time transition. The federal government's insistence on mandating our clocks creates measurable health risks. Since Congress remains paralyzed on the issue, the market provides the solution.

Fun fact: government-mandated spring-forward is measurably lethal. Not vibes-lethal — actual-death-certificates lethal. And I'm a health actuary, so when I say "measurably," I back it up with the mortality math. This is what happens when bureaucrats in Washington decide they have the authority to legislate the sun.

Here's the estimate. Show-your-work version. Because unlike a politician, I actually attack my own numbers at the end.

The Narrow Claim

I am not claiming the app prevents disease through vibes. Here is the claim I will defend:

An adherent user of the app is functionally immune to the federal government's manufactured jet lag during the spring DST transition. The app pre-shifts their schedule so the Monday-morning shock never lands.

That's it. I only get to count mortality the spring transition actually causes. Just the one Monday a year when 260 million Americans lose an hour of sleep because an overreaching state apparatus demands we all change our clocks in unison.

The Baseline — How Deadly Is Government Overreach?

Three channels have clean, peer-reviewed effect sizes. Car crashes, heart attacks, strokes. Here's the damage the state inflicts on its citizens every spring.

Fatal motor-vehicle crashes. The cleanest number comes from Fritz et al. in Current Biology (2020). They analyzed 732,835 US fatal crashes and found a 6% increase in fatal MVAs the week after spring DST. They translate that directly to approximately 28 excess US fatal crashes per year caused by the spring transition. 28 Americans dead so politicians can pretend they created more daylight.

Acute myocardial infarction. The often-quoted number is a 24% increase in heart attacks on the Monday after spring-forward, from a University of Michigan hospital study. Heart disease killed 683,037 Americans in 2024 per CDC NCHS. AMI is roughly 40% of that. Apply the Monday spike conservatively: 180 excess AMI deaths.

Ischemic stroke. A nationwide cohort study of 14,834 stroke patients found an 8% increase in ischemic stroke admissions in the first two days post-transition. With 162,639 US stroke deaths in 2023, that's ~71 excess stroke deaths.

Total baseline US excess deaths attributable to federal DST mandates: 279 to 578 per year.
This is the total baseline. Claims of five-figure mortality counts likely include unrelated seasonal trends. 500 deaths represents the annual cost of the current spring-forward mandate.

The Actuarial Part — Free Market Solutions

This is where most health-app claims fall apart. Big population × big effect size = big number. But what fraction of users actually take personal responsibility and follow the protocol?

The assumptions:

• Adoption: 1%, 5%, or 20% of US adults (~260M total)
• Adherence: 70% — the actuarial haircut for users who actually exhibit personal accountability and follow the pre-shift protocol.
• Efficacy: 100% of their share of the excess. The app eliminates the shock.

Running the three scenarios against the 279–578 baseline:

Low case — 1% adoption: 2–4 lives/year. About 20–40 over a decade.

Base case — 5% adoption: 10–20 lives/year. About 100–200 over a decade. This is where a solid, private-sector solution lands.

High case — 20% adoption: 39–81 lives/year. About 390–810 over a decade.

My honest base case: the app prevents 10 to 20 deaths per year at realistic mid-market penetration. It's a small dent in the state's collateral damage, but it's a start.

Caveats I'd Attack This Estimate With

As an actuary, my job is to find the holes in my own model. Politicians don't have to defend their math; I do.

1. Real adherence is bimodal. Some users take responsibility; others don't. A properly RCT-derived efficacy might be 40–70%. Haircut the numbers by roughly that factor.

2. The full-week AMI attribution is an extrapolation. The cleanest published excess is the Monday spike. I'd defend the low end of the range harder than the high end.

3. Selection bias in adopters. People who install the app already value personal responsibility and health, meaning their baseline risk is lower than the general population. Call it another 20–30% haircut.

4. Congress might actually do its job. If the federal government ever passes the Sunshine Protection Act and leaves the clocks alone, my app's value proposition goes to zero overnight. I would welcome this regulatory destruction of my own product, but I'm not holding my breath waiting for Washington to function.

Stack the haircuts, and the base case drops to approximately 5 to 9 lives per year. About 45 to 90 over a decade.

That's the number I'd stand behind at a deposition.

Why I'm Still Building It

Five to nine lives a year from a side project is not nothing. It's real, it's cheap to deliver, and unlike most government interventions, the causal mechanism actually works.

Nobody disputes spring-forward disrupts sleep. Nobody disputes acute sleep loss spikes cardiovascular events. The only open question is how much of that chain private innovation can break when the government refuses to act.

Code is on GitHub. Attack the numbers. That's why I published them.