A Century-Long Debate: The Origins and Evolution of Daylight Saving Time

Perhaps the most chronic, cyclical debate is the existence of Daylight Saving Time. Typically, you hear about it most in the late winter as we “spring forward,” losing an hour of sleep. The change on the body is no different than shifting time zones while traveling, and contrary to belief, there is no effect on temperature or weather patterns. The shift in springing forward simply moves the daylight one hour later as opposed to adding an hour of daylight.

The implementation of Daylight Saving Time (DST) stems back to World War I, used as an energy-saving measure – it was one less hour in the evening when electric lights were used. Also known as “War Time,” it wasn’t very popular, and jurisdictions were allowed to choose what time – Standard or DST – they preferred after the war. As you can imagine, that led to quite a mess, as cities and towns in the same state were occasionally running at different times.

The change in time was again mandated in World War II, but it wasn’t until the Uniform Time Act of 1966 that our current system was established. However, Hawaii and Arizona, along with many U.S. Territories, do not observe DST.

While many argue we should not “spring forward” and “fall back,” those alive in the 1970s lived through the most recent year without clock changes. Referring back to the notion that DST was energy-saving, it was imposed year-round in 1973 during the global oil crisis. It lasted only that one year. The sunset timing was not the problem, but rather the sunrise that ultimately led to the return of switching in fall and spring (though now late winter, after a law in 2007 shifted the “spring forward” up three weeks).

For example, without falling back in the fall, Boston’s sunrise in the depths of winter wouldn’t be until 8:15 am. As you move farther west in a time zone, that time only gets later. It’s a problem for schools and children waiting for buses with class times starting between 7:30 and 8:30 am. In addition, without springing forward, sunrises in the summer would be closer to 4:00 am. For these reasons, permanent Standard or DST has never succeeded for more than a year.

Meteorological Impact and Forecasting Efficiency

Meteorologically, the only thing that changes is the time of day that we hit high or low temperatures. The physical temperature patterns or averages do not change, nor do the global weather patterns. Often time meteorologists are excited to “fall back” in November, as this means we receive our model data one hour earlier than before. When forecast times are finite, having an extra run of data can provide increased context to a forecast, especially during the winter storm season.