Because moving the clock forward one hour hits your body like a mild case of jet lag. You lose an hour of sleep, and your internal clock falls out of step with the new schedule, a mismatch called circadian misalignment. The result can be grogginess, brain fog, and a short fuse for days afterward.
What the Spring Clock Change Does to Your Body Clock
Your body runs on an internal clock that keys off light and dark. When clocks jump ahead, your schedule shifts one hour but your biology doesn’t. The American Academy of Sleep Medicine says daylight saving time is less aligned with human circadian biology, and that the delayed natural light and dark cycle can cause circadian misalignment, which some studies link to cardiovascular disease, metabolic syndrome, and other health risks.
That mismatch, plus an hour less sleep, explains the fog. You wake while your body still behaves as if it’s the middle of the night, and it takes time for your clock to catch up.
What Research Shows About the Spring Change
The AASM position statement describes the sudden shift to daylight saving time as carrying significant public health and safety risks, including a higher chance of cardiovascular events, mood disorders, and car crashes. In a 2019 AASM survey, 55 percent of adults said they felt extremely or somewhat tired after the spring change. The AASM also cites traffic fatalities rising by as much as 6 percent in the first few days, and an 18 percent increase in adverse medical events tied to human error in the week after the switch.
Those figures describe populations, not your personal fate. They do show that feeling wiped out is common and measurable, not a lack of willpower.
How to Ease Into the Time Change
Small steps can soften the shift:
- Move your bedtime and wake time earlier by about 15 minutes over the few days before the change
- Get bright light soon after waking, ideally outdoors
- Keep meals, workouts, and bedtime on a steady schedule
- Limit late-day caffeine and alcohol, which can disrupt sleep
- Keep naps short, around 20 minutes, and early in the afternoon
Why Sleep Experts Want to End Clock Changes
The AASM calls for abolishing seasonal clock changes in favor of a fixed, year-round standard time. It also notes that the long-term effects of staying on daylight saving time year-round are not well studied. If your fatigue lingers well after the adjustment, our guide to why you’re tired all the time even when you sleep enough covers other possibilities.
Supporting Energy While Your Body Clock Catches Up
Light, timing, and sleep matter most, but some people also support how their cells make energy during a rough week. Performance Lab Energy is a caffeine-free formula with magnesium malate, acetyl L-carnitine, R-lipoic acid, CoQ10, PQQ, and BioPerine, ingredients involved in how mitochondria produce cellular energy. It supports energy without stimulants, so it won’t interfere with an earlier bedtime the way late-day caffeine can.
Frequently Asked Questions
Does Daylight Saving Time Affect Mood?
The AASM links the spring clock change to a higher risk of mood disorders, along with cardiovascular events and car crashes.
Is the Spring Change Linked to More Car Crashes?
The AASM cites traffic fatalities rising by as much as 6 percent in the first few days after the change.
What Do Sleep Experts Recommend?
The AASM recommends ending seasonal clock changes in favor of a fixed, year-round standard time.
