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Study Reveals Daylight Saving Time Harms Health, Advocates Change

9/16/2025

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Summary

Story summary

A Stanford Medicine study indicates that biannual clock changes for daylight saving time may negatively impact Americans' health.
The research finds that permanent standard time is more beneficial than the current system, potentially preventing 300,000 strokes and reducing obesity by 2.6 million cases annually.
Permanent daylight saving time could provide about two-thirds of these benefits.
The study highlights the significance of morning light for circadian health, noting that evening light can disrupt it.
Researchers advocate for more interdisciplinary studies to explore the broader implications of time policy decisions.

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Story summary

A Stanford Medicine study indicates that biannual clock changes for daylight saving time may negatively impact Americans' health.
The research finds that permanent standard time is more beneficial than the current system, potentially preventing 300,000 strokes and reducing obesity by 2.6 million cases annually.
Permanent daylight saving time could provide about two-thirds of these benefits.
The study highlights the significance of morning light for circadian health, noting that evening light can disrupt it.
Researchers advocate for more interdisciplinary studies to explore the broader implications of time policy decisions.