Daylight Saving Time (DST) has a century-long history, though it is not practiced in every country.  Twice a year, clocks are reset backwards or forwards by an hour.  It’s a hassle for public transport, and humans experience a one-hour jetlag. The initial idea was to save electricity by extending daylight hours. It just doesn’t do so — or at least a reduction was found only in some countries (Norway and Sweden) whereas in Indiana the demand for electricity actually increased.)

Over the last year the call to abolish DST has become stronger, with heated arguments in different directions. California voted for year-round DST. This generally seems to be “emotionally” and spontaneously the most popular.  However, chronobiologists from all over the world in their scientific organizations have now prepared arguments explaining the different sunlight scenarios in winter and summer on “Standard Time” vs. DST. Standard Time follows the natural course of the sun at any given latitude and is the solution that should be aimed for. It will be interesting to see which countries listen to those who know best how sunlight affects human behavior and health. 


The Society for Research on Biological Rhythms (SRBR) has prepared a Daylight Saving Time (DST) Press Kit for the public. Here you can find all you ever wanted to know about the health and social consequences of DST:

  • Scientific arguments in a position paper.
  • An infographic showing how where we live in a time zone also modifies our “sun time” in DST and Standard Time (from the UCSD BioClock Studio).
  • Talking points: why we care about DST.
  • A collection of articles on DST and its impact on biological clocks, sleep and public health.
  • A list of references to scientific articles that have studied how DST affects circadian rhythms, sleep, and overall health).

NEW! A signed letter in support of permanent Standard Time (and not permanent Daylight Saving Time) by the American Academy of Sleep Medicine (AASM), Society of Behavioral Sleep Medicine (SBSM) and Society for Research in Biological Rhythms (SRBR), April 2022.



Escape the Burden of Switching to Daylight Time

Our inner clock doesn’t know that the government has rescheduled our lives.

A blog post by Michael Terman, PhD