After providing testimony to the Texas House State Affairs Committee on March 13, it became apparent that in order to succeed in my quest to end Daylight Saving Time in Texas, I needed more friends.

I found the Society for Research on Biological Rhythms (SRBR). Working my way down the list of members of the society on the Government Affairs Committee, I was able to reach Dr. Erik Herzog. It turns out that Dr. Herzog is the President of the Society.

He graciously agreed to send a letter supporting the end of Daylight Saving Time in Texas, and a few days later he sent the following email:

Dear Representative,

I write on behalf of the 1,000 scientists, physicians and industry representatives who are members of the Society for Research on Biological Rhythms (SRBR).  We appreciate your bold leadership in seeking to end the “fall back” and “spring forward” associated with DST. This negatively affects the health and safety of 1.6 billion people around the world. Critically, based on a number of replicated scientific studies, we support permanent Standard Time, not permanent Daylight Saving Time.  Below, please find our statement with references to the peer-reviewed science. Please revise your bill to keep ST starting next fall.  We are happy to work with you on this campaign to end DST and the associated months of sleep loss and increased health risks. 


Erik Herzog

Professor of Biology and Neuroscience

President of the Society for Research on Biological Rhythms

Chronobiology studies the influence of day-night rhythms and seasonal changes in living organisms (and received the Nobel Prize 2017 for these discoveries).  As experts in biological clocks and sleep, we have been following the initiative of the European Commission to abandon the annual clock-time changes in spring and autumn in the EU.  We would like to emphasize that the scientific evidence presently available indicates that installing permanent Standard Time (ST, or ‘wintertime’) is the best option for public health.

With ST there will be more morning light exposure in winter and less evening light exposure in summer. This will better synchronise the biological clock and people will sleep earlier relative to their work and school times (1). The feeling of chronic jetlag (Social Jetlag) will be reduced compared to Daylight Saving Time (DST), the body will function better and mental performance will improve. Throughout the year, ST will be healthier than DST.

ST improves our sleep (1) and will be healthier for our heart (2) and our weight (3). The incidence of cancer will decrease (4), in addition to reduced alcohol- and tobacco consumption (5). People will be psychologically healthier (6) and performance at school and work will improve (7). Abandoning clock changes will offer the unique nation-wide opportunity to improve general health by installing Standard Time.

We would gladly explain our advice in more detail as required.


European Biological Rhythms Society 

Society for Research on Biological Rhythms

1)            Kantermann et al. (2007) The human circadian clock’s seasonal adjustment is disrupted by daylight saving time. Current Biology 17:1996-2000.

2)            Merikanto et al. (2013) Associations of Chronotype and Sleep With Cardiovascular Diseases and Type 2 Diabetes. Chronobiol.Int. 30:470-477.

3)            Roenneberg et al. (2012) Social Jetlag and Obesity. CURRENT BIOLOGY 22: 939-943.

4)            Borisenkov (2011) Latitude of Residence and Position in Time Zone are Predictors of Cancer Incidence, Cancer Mortality, and Life Expectancy at Birth. Chronobiol.Int. 28: 155-162.

5)            Wittmanm et al (2006) Social jetlag: Misalignment of biological and social time. Chronobiol.Int. 23:497-509.

6)            Borisenkov et al. (2017) Seven-year survey of sleep timing in Russian children and adolescents: chronic 1-h forward transition of social clock is associated with increased social jetlag and winter pattern of mood seasonality. Biological Rhythm Research 48:3-12.

7)            Van der Vinne (2015) Timing of Examinations Affects School Performance Differently in Early and Late Chronotypes. Journal of Biological Rhythms 30:53-60.


Erik Herzog              

Dept. of Biology      

Washington Univ.  

St. Louis, MO 63130