Twice a year, we move the clocks – and twice a year, safety teams see the effects on the job. The change is only one hour, so it’s easy to dismiss. But the research is clear: that lost hour in the spring shows up in real-world injury data, and the fall transition brings its own set of hazards that are just as easy to overlook.

The good news? The risk is predictable, and it’s preventable. Here’s what’s happening and what you can do about it.

The Science Behind the “Lost Hour”

When we spring forward, we lose an hour of sleep and our bodies don’t reset overnight. A well-known study of mining injury data from 1983 to 2006 found that on the Monday directly after the switch to daylight saving time, workers sustained more workplace injuries, and more severe ones, than on other days. On those same Mondays, workers slept about 40 minutes less than usual.

That’s the key detail: the spring change cuts into sleep, and it’s the sleep loss, not the clock itself, that drives the risk. Put in broader terms, workplace injury data gathered over that same period showed injuries increased by about 5.7% in the days following the spring time change.

The Fall Transition – Different But Not Risk-Free

It’s tempting to relax when we “gain” an hour back in November. But the fall change has its own set of challenges.

• A disrupted schedule, not a longer sleep. Gaining an hour doesn’t mean people actually sleep more. Many people stay up later, or simply don’t adjust, and the shift in their body clock (circadian rhythm) can leave them just as groggy (especially when it lands on a weekend) so workers return to the job on a Monday with a misaligned schedule.
• The darker commute. After falling back, it gets dark earlier, and for many crews that means driving home in darkness. Visibility drops, and drowsy-driving risk combines with reduced light to make the evening commute more dangerous.
• Early darkness on the job site. For outdoor work in construction and agriculture, the earlier sunset shortens daylight hours for tasks and can increase hazards tied to poor visibility: equipment operation, traffic control, and work around moving machinery.
• The longer adjustment. Circadian realignment after either change can take about a week, and it tends to be harder for older workers and those with irregular or rotating shifts.

The spring change is sharper with a more measurable spike in injuries, but the fall change quietly raises risks through darkness and schedule disruption.

Why Daylight Saving Affects Safety So Intensely

Fatigue is already a major factor in safety-critical work. The National Safety Council reports that 13% of workplace injuries can be attributed to fatigue, and that nearly every worker in America carries at least one fatigue risk factor. Jobs involving heavy equipment, moving parts, heights, and repetitive physical work are exactly the settings where a slower reaction time or a lapse in judgment can turn into a serious injury.

Risks to Watch For

• More workplace injuries in the days after the spring change, with injuries that tend to be more severe.
• Drowsy driving after both transitions, and darker evening commutes after the fall change.
• Reduced visibility in the early morning after springing forward, and in the early evening after falling back.
• A longer adjustment period for older workers and rotating-shift crews.

What You Can Do About It

The most effective move is to treat each transition like the predictable event it is.

• Encourage workers to adjust their sleep in advance. Shifting bedtime by 15–20 minutes for a few days before the change helps ease the body into the new schedule, with a goal of at least seven hours of sleep.
• Schedule the hardest work smartly. After springing forward, plan the most demanding tasks for later in the day and keep Monday lighter where possible. After falling back, make the most of daylight hours and plan around the earlier sunset.
• Watch the low-visibility shifts. Pay extra attention to pre-dawn starts in the spring and the evening commute in the fall. Make sure lighting, high-visibility gear, and site lighting are dialed in.
• Make fatigue acceptable to talk about. Encourage workers to report drowsiness without fear of penalty — a tired worker who speaks up is safer than one who pushes through.
• Add a commute check. Remind crews about drowsy driving after both changes and consider staggering start times or offering a place to rest before driving home.

The Takeaway

Daylight saving time is a small change with an outsized effect on safety. The spring transition brings a sharp spike in injuries; the fall transition quietly raises risks through darkness and disrupted schedules. By understanding the science and planning around each change, you can protect your crew through both and keep the job moving safely.

OCTOBER 2026