Yes, even a small loss of sleep was linked with more phishing clicks in a 2026 study. In PNAS, a UC Irvine neurobiologist sent a simulated phishing email to 11,218 employees, at random either on the Monday after the spring switch to daylight saving time or a week earlier. After the switch, clicks rose about 13%.
Key takeaways
- In a randomized, blinded field experiment published in PNAS in November 2026, 11,218 University of California, Irvine employees received a simulated phishing email on one of two Mondays.
- On the Monday after the spring 2026 switch to daylight saving time, 17.76% clicked the suspicious link, against 15.56% a week earlier: about 13% more.
- The sleep loss changed clicking only: people were no more likely to open the email, and no less likely to report it as spam.
- Earlier research found that workers sleep about 40 minutes less on the Monday after the spring clock change.
- One change to make: shift bedtime and wake time 15 minutes earlier on each of the few nights before a spring clock change, so you arrive with no lost sleep.
What did the 2026 phishing and sleep study find?
A short loss of sleep was followed by more risky clicks. Eitan Schechtman, a neurobiologist at the University of California, Irvine, used the spring clock change as a natural way to take a little sleep from thousands of people at once, then measured how they handled a fake phishing email.
| Study detail | What it was |
|---|---|
| Journal | Proceedings of the National Academy of Sciences (PNAS), November 2026 |
| Design | Naturalistic experiment with random assignment and blinding |
| People | 11,218 employees of the University of California, Irvine |
| What changed | A simulated phishing email arrived either on the Monday after the spring 2026 switch to daylight saving time or one week earlier |
| Main result | Click rate 17.76% after the switch vs 15.56% before, about a 13% rise |
| No change | Opening the email, or reporting it as spam |
The emails came from the institution’s regular cybersecurity awareness program, which sends look-alike phishing messages every few months to teach staff what to watch for. Because people were assigned to a Monday at random and did not know they were being studied, the difference points to the clock change rather than to who got the email.
Why would one lost hour change what you click?
Sleep loss dulls the checks that slow down a quick decision. The study’s abstract notes that restricted sleep impairs thinking across many areas, and the result fits that picture: people still opened the email at the usual rate and still reported it at the usual rate, but more of them clicked.
The UC Irvine news release on the study puts it plainly. Schechtman said, “Better sleep likely leads to better decisions.” He also compares the sleep lost to the clock change with the small shortfalls many people run up on ordinary nights.
The spring change is a known sleep thief. In a 2009 Journal of Applied Psychology study, US time-use records showed workers slept about 40 minutes less on the Monday after the switch to daylight saving time, and mining injuries rose that day. A 2012 study by the same group found that the switch was followed by more cyberloafing, time spent on unrelated websites during work. The autumn change, which adds an hour, showed no drop in sleep in the 2009 data.
Is daylight saving time bad for your health?
The spring transition carries real risks, according to the American Academy of Sleep Medicine. Its 2020 position statement links the move to daylight saving time with a higher risk of adverse cardiovascular events, mood disorders and motor vehicle crashes. The academy’s stated position is that seasonal clock changes should end in favor of a fixed, year-round standard time, which it says is better aligned with human circadian biology. For as long as the clocks still change, the lost hour has to be absorbed by your body clock. For background on how clock time drifted away from the sun, see The Day of Two Noons, and for the autumn date, When Does Daylight Saving Time End?.
What is the one change to make?
Shift your sleep 15 minutes earlier on each of the few nights before the spring clock change, so the lost hour is already behind you when the clocks jump. This follows the Society of Behavioral Sleep Medicine’s advice; the 2026 study measured the cost of lost sleep, not this fix.
- About four nights before the change, move lights out and your alarm 15 minutes earlier, and keep moving both by 15 minutes each night.
- Start your wind-down, and put screens away, 15 minutes earlier as well.
- Move meals and other daily anchors earlier along with your sleep.
- On the morning after the change, get outside in sunlight, which helps the body clock settle at the new time.
- If you do arrive short on sleep, give links and payment requests in your inbox a second look before you click.
The same habit helps after any short night, from a late holiday party to a big game. For a full reset, read How to Fix Your Sleep Schedule and Does an Earlier Bedtime Help?, and for moving a whole plan at once, How to Adjust Day Plans for a Clock Change in Owaves. Take the Body Clock Type quiz to see where your natural sleep window falls.
Your day on My BodyClock
The day above on My BodyClock is one of the nights before a spring clock change, with sleep already moved earlier: wind-down at 9:15 PM, lights out at 10 PM and a 6:15 AM wake. A walk in morning daylight and breakfast lead into focused work, with email given its own late-morning block. Short pink Flow blocks hold getting ready, the commute and setting out clothes, and every block runs into the next so the full 24 hours are planned.
Build your own version in Owaves: My BodyClock on the App Store, or join the Android waitlist.
FAQ
Does lack of sleep make you more likely to fall for scams?
A 2026 PNAS experiment with 11,218 university employees suggests it does. A simulated phishing email sent on the Monday after the spring clock change drew about 13% more clicks than the same kind of email sent a week earlier (17.76% vs 15.56%). Opening the email and reporting it as spam did not change.
How much sleep do people lose when the clocks spring forward?
Up to an hour. A 2009 study of US time-use data found that on the Monday after the switch to daylight saving time, workers slept about 40 minutes less than on other days. The switch back to standard time in autumn showed no such loss.
How do you adjust to daylight saving time?
Start a few nights early. The Society of Behavioral Sleep Medicine advises moving bedtime and wake time earlier in 15-minute steps over several nights, shifting meals and other daily activities earlier too, and getting sunlight on the morning after the change.
Does this only matter when the clocks change?
No. The clock change was simply a clean way to test a small, shared loss of sleep. The study’s author says it is similar in scope to the sleep many people lose on ordinary nights, and points to holidays and big sports events as other times when sleep runs short.
Sources
- Schechtman E. Modest loss of sleep increases susceptibility to cybersecurity threats. Proceedings of the National Academy of Sciences, November 2026;123(46):e2622467123. doi:10.1073/pnas.2622467123. https://pubmed.ncbi.nlm.nih.gov/43013551/
- University of California, Irvine. Modest loss of sleep raises email phishing risk. EurekAlert!, 9 November 2026. https://www.eurekalert.org/news-releases/1150614
- Barnes CM, Wagner DT. Changing to daylight saving time cuts into sleep and increases workplace injuries. Journal of Applied Psychology, September 2009;94(5):1305-1317. doi:10.1037/a0015320. https://pubmed.ncbi.nlm.nih.gov/19702372/
- Wagner DT, Barnes CM, Lim VK, Ferris DL. Lost sleep and cyberloafing: evidence from the laboratory and a daylight saving time quasi-experiment. Journal of Applied Psychology, September 2012;97(5):1068-1076. doi:10.1037/a0027557. https://pubmed.ncbi.nlm.nih.gov/22369272/
- Rishi MA, Ahmed O, Barrantes Perez JH, et al. Daylight saving time: an American Academy of Sleep Medicine position statement. Journal of Clinical Sleep Medicine, 15 October 2020;16(10):1781-1784. doi:10.5664/jcsm.8780. https://pmc.ncbi.nlm.nih.gov/articles/PMC7954020/
- Society of Behavioral Sleep Medicine. Adjusting to Daylight Saving Time. https://behavioralsleep.org/index.php/society-of-behavioral-sleep-medicine-blog/281-adjusting-to-daylight-saving-time
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