sunshine protection act still stalled.
In 2025, a Stanford study compared the year-long circadian health impact of permanent standard time, permanent daylight saving time, and biannually switching in the continental U.S. using models of the human circadian rhythm and health data from the CDC Places dataset. Researchers found that switching to permanent standard time was predicted to reduce cases of obesity by 2.6 million cases and stroke by 300,000 cases. Permanent daylight saving time also reduced cases but to a lesser extent.[38] In interviews, the authors caution that this work is from a circadian health perspective and that other factors should be considered in policy decisions such as economic and safety impacts of time policy.