October 30th, 2019
An Open Letter to the BC Government in Support of Permanent Standard Time
Local and national governments around the world are considering proposals to eliminate the
time change in favour of permanent Daylight Saving Time (DST) or Standard Time. Earlier this
year, the BC government invited the public to share their views in a poll but provided no option
to vote for permanent Standard Time. Yet, experts in biological rhythms and sleep unanimously
agree that Standard Time year-round is the best option for public health and safety (see
attached position papers from various biological rhythms societies as well as a list of references
to scientific articles).
If DST is kept year-round, sunrise would be later in the winter, leading to decreased exposure to
morning sunlight. Under permanent DST, Vancouverites will get 67 fewer days of morning light
(sunrise by 0800h) compared to permanent Standard Time (see Figure below). BC children will
have to commute to school in the dark for about a third of the school year.

Source: Slide presented by Dr. Kenneth Wright at the 2019 World Sleep
Congress in Vancouver. Included with permission of the author.

Our body's internal biological clock needs exposure to morning light. When exposure to sunlight
in the morning is reduced, our biological clock drifts later, making it harder to wake up and
causing an increased mismatch between the body clock and local time (a condition called social
jetlag). DST also exposes people to more evening light, which further delays the biological clock
and makes it more difficult to fall asleep. Both sleep deprivation and social jetlag are associated
with negative effects on physical and mental health outcomes, including increased risks for
diabetes, obesity, heart disease, depression, and some forms of cancer. In children and
adolescents, sleep deprivation and social jetlag are associated with poor academic
performance, absenteeism and substance use. Lack of sleep and fatigue also increase the risk
of accidents during commutes and on the job. Therefore, permanent DST in BC is expected to
have adverse long-term implications for public health and safety.
We call upon the Government of British Columbia to reconsider its commitment to permanent
DST. As experts in circadian biology, sleep, mental health and safety, we understand that
removing the time change in favour of permanent Standard Time is the preferred option.

Sincerely,

 Myriam Juda, PhD
Research Associate, Sleep and Circadian Neuroscience Lab,
Psychology, SFU
Ralph Mistlberger, PhD
Professor, Psychology, SFU
Director, Sleep and Circadian Neuroscience Lab, Psychology, SFU
Andrea Smit, PhD, on behalf of the Canadian Society for Chronobiology (CSC)
Member of the CSC Board of Directors
Najib Ayas, PhD, MD, MPH, FRCPC
Associate Professor of Medicine, Sleep Disorders Program
Faculty of Medicine, The University of British Columbia
Judy Village, PhD, CCCPE
President, Association of Canadian Ergonomists
Adjunct Professor, School of Population and Public Health, UBC
Raymond Lam, PhD, MD, FRCPC
Professor and BC Leadership Chair in Depression Research
Associate Head of Research, Psychiatry, University of British Columbia
Director Mood Disorders Center, Djavad Mowafaghian Center for Brain Health
Executive Director, APEC Digital Hub for Mental Health