Daylight Saving Time will commence at 2:00 a.m. Sunday in most places in the United States and at 1 a.m. Sunday, March 28, in most places in Western and Central Europe. Along with the annual ritual of springing forward and advancing our clocks by an hour, Daylight Saving Time also sparks an annual ritual of scrutinizing the rationale for this policy.
Although advancing clocks by a single hour seems relatively trivial, a vast body of research on the practice indicates that Daylight Saving Time has dramatic effects on a wide range of outcomes—from traffic fatalities to stock market performance.
Within the workplace, organizational behavior researchers have used Daylight Saving Time as a vehicle for studying the effects of people’s sleep behavior and quality on their individual work outcomes, as well as the kinds of relationships that they have with their colleagues.
Researchers who study this topic underscore the critical role that sleep quality and quantity have on leaders’ and employees’ productivity, attitudes and relationships.
For example, in one study described in a New York Times editorial, researchers assessed the impact of Daylight Saving Time on injuries in the mining industry between 1983 and 2006.
The authors found that the simple Daylight Saving shift of one hour, which they identified as contributing to a true decrement in sleep, was associated with a higher number of workplace injuries and an increase in the severity of injuries.
A core mechanism that contributes to these effects is the human circadian rhythm and the entrainment of the sleep cycle to social and environmental “pacers.” One of these pacers is clock time in society. However, whereas the pacing of a clock can be immediately adjusted—it occurs at the moment that Daylight Saving Time begins—people’s internal clocks are inertial.
If you have traveled by plane across time zones, you have no doubt experienced this internal inertia in the form of jet lag. When you experience jet lag, you are experiencing a mismatch between your internal clock and the pacers that are in your new social context. Daylight Saving Time is a less extreme—but no less impactful—shift that creates a small misalignment between your internal clock and the external environment.
The implication of even a minor shift of one hour is that people tend to get less sleep than they usually would in the week following the start of Daylight Saving Time. When the alarm clock rings at 6:00 a.m. on Sleepy Monday, your body is still operating as though it is 5:00 a.m.
Further, you likely went to bed at your usual time, following your pre-Daylight Saving Time adjusted clock. Having a workforce that is slightly sleep-deprived has subtle but important effects on the workplace. Compared to when they are fully rested, people who are sleep deprived are more negative and abusive toward one another, more prone to committing small ethical lapses and less focused and productive in their own work.
In all, the evidence on the effects of Daylight Saving Time on the quality of people’s at-work experiences is clear and compelling. A simple loss of an hour in the day degrades people’s individual work and generates friction in their interpersonal relationships.
For these reasons, workplace researchers who study sleep often advocate strongly for the elimination of Daylight Saving Time. As a leader, perhaps lacking the power to broadly eliminate Daylight Saving Time, one local policy could be to encourage—where possible—a later start time on Sleepy Monday.
And, for everyone, one practice to enrich the workplace is to simply get more sleep.