Daylight Saving Time Starts This Weekend; Health Risks and Practical Steps to Prepare
Daylight saving time begins at 2 a. m. local time on Sunday, March 8, when most states will set clocks forward one hour, effectively shaving an hour from sleep for many people. That shift matters now because research links the spring change to heightened risks for heart attacks and deadly car crashes, and public-health experts are urging simple preparations to blunt the impact.
Daylight Saving Time: When it begins, who opts out and how long it lasts
The nationwide switch takes effect in the early morning hours on Sunday, March 8; clocks are set forward one hour and the period continues until the end of standard time on Sunday, Nov. 1, when clocks will be set back. For many, devices will update automatically, but officials advise manually turning clocks ahead Saturday night to avoid confusion.
Observance is not universal. Hawaii and most of Arizona do not change clocks; the Navajo Nation in Arizona is an exception to that state's general practice. U. S. territories that do not observe the change include American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the Virgin Islands. Internationally, participation varies: for example, British Columbia’s Premier David Eby has announced his province will switch to permanent daylight time, adopting a new Pacific Time designation.
Dr. Keisha Sullivan and University of Colorado Boulder findings on health and safety
Medical and transportation research links the spring forward to measurable harms. Dr. Keisha Sullivan, a sleep medicine physician at Kaiser Permanente, warns that the abrupt one-hour loss of sleep can impair focus and elevate cardiovascular risk: research shows an increase in heart attacks during or after the spring clock change. Separate studies, including work by the University of Colorado Boulder, find the transition corresponds with a rise in deadly car accidents.
The causal chain is straightforward: shifting the clock forward reduces sleep for many people, which degrades alertness and can worsen cardiovascular health; reduced sleep also elevates the likelihood of driving errors, increasing accident risk. What makes this notable is that even a single-hour shift produces statistically observable changes in public health and road safety, prompting medical experts to recommend mitigation steps.
Practical steps recommended by sleep experts to prepare
Sullivan lays out specific, incremental adjustments to help the body adapt before the clock change. Start by moving bedtime earlier by 15 minutes each night: by night two you will be about 30 minutes earlier than usual, and continuing that pattern can ease the transition into the one-hour advance. Other concrete measures include avoiding caffeine for at least six hours before bedtime and cutting screen time one to two hours before lights out.
On waking, exposure to sunlight is advised because natural light suppresses melatonin and helps increase alertness. Sullivan also stresses maintaining consistent sleep and wake times every day, including weekends, and emphasizes that chronic insufficient sleep can cause memory problems, weight gain and increased food cravings.
Legislative moves and the broader picture
Policy discussions continue alongside these immediate preparations. Federal efforts to make the practice permanent have been introduced in recent sessions; the Sunshine Protection Act was reintroduced in January 2025 but remains stalled in congressional committees. In February, Rep. Greg Steube introduced the Daylight Act of 2026, demonstrating ongoing interest in changing the schedule nationally, even as state-level proposals for permanent standard time and permanent daylight saving time remain nearly evenly split.
For now, the practical reality is the recurring clock change. Individuals can reduce short-term risks by shifting sleep schedules gradually, avoiding late-day stimulants, limiting evening screens and seeking morning light—simple actions intended to blunt the demonstrable uptick in heart events and traffic fatalities that follow the spring transition.
