The traditional 40-hour workweek is composed of five eight-hour days instead of four ten-hour days. But the historical reasons for that are fairly arbitrary, and trying to get firms to switch to a four-day workweek has long struck me as a relatively painless way to reduce gasoline consumption. Brad Plumer lets us know that the state of Utah actually tried this and had state employees take Friday off and work longer hours the other four days of the week. According to Scientific American the results were impressive:
For those workplaces, there’s no longer a need to turn on the lights, elevators or computers on Fridays — nor do janitors need to clean vacant buildings. Electric bills have dropped even further during the summer, thanks to less air-conditioning: Friday’s midday hours have been replaced by cooler mornings and evenings on Monday through Thursday. As of May, the state had saved $1.8 million. …
An interim report released by the Utah state government in February projected a drop of at least 6,000 metric tons of carbon dioxide emissions annually from Friday building shutdowns. If reductions in greenhouse gases from commuting are included, the state would check the generation of at least 12,000 metric tons of CO2 — the equivalent of taking about 2,300 cars off the road for one year.
Another variant of this, discussed by Aaron Newton, would be staggered four-day workweeks that could substantially cut down on traffic congestion (a smaller proportion of the population commuting on any given day) at the expense of reducing the gains in building energy efficiency.