Environ Resource Econ (2018) 70:517–543
Does Daylight Savings Time Save Energy? Evidence from
Accepted: 7 March 2017 / Published online: 21 March 2017
© Springer Science+Business Media Dordrecht 2017
Abstract Daylight savings time was adopted for the purposes of reducing energy consump-
tion, but recent studies have cast some doubt on whether it still serves this purpose effectively.
This study estimates the effect of daylight savings time on electricity demand in Ontario,
Canada. It uses a quasi-experimental approach, by leveraging the fact that the transition to
DST occurs on a different day in each year. The results suggest that daylight savings time
reduces the demand for electricity by about 1.5% in Ontario. The reductions in electricity
consumption is concentrated during the evening period. The reduction in electricity demand
appears to persist for at least several weeks following the transition to daylight savings time.
Keywords Daylight savings time · Energy demand · Natural experiment
Daylight savings time (DST) is a controversial practice. The policy was originally imple-
mented to save energy, but DST has since been associated with a number of side effects.
For example, studies have suggested that by disrupting sleep patterns (Kantermann et al.
2007), DST causes additional trafﬁc accidents (Smith 2016; Sood and Ghosh 2007), reduces
self-reported well-being (Kuehnle and Wunder 2014; Kountouris and Remoundou 2014),
lowers ﬁnancial market returns (Kamstra et al. 2000), as well causes as a number of health
and other social impacts (Lahti et al. 2008; Janszky et al. 2012; Barnes and Wagner 2009;
Doleac and Sanders 2015). Every year, during the spring transition from Standard Time to
Daylight Saving Time, and during the reverse transition in the fall, media draw attention to
these side effects of DST. As a result, the practice is regularly questioned.
Surprisingly, while the original purpose of DST was to reduce energy consumption, there
is still no consensus about the actual impact of the practice on energy consumption. In
Graduate School of Public and International Affairs and Institute of the Environment, University of
Ottawa Faculty of Social Science, 90 University Ave, Ottawa, ON, Canada