From 1964 to 1999, all of the major goods-producing industries—mining, construction, and manufacturing—added hours to their average workweeks. In contrast, all of the major service-producing industries lost hours from their workweeks.
In both mining and construction, average weekly hours per job rose by 1.9 hours between 1964 and 1999; in mining, the average workweek was the longest of all the industries in 1999, at 43.8 hours. The average workweek went up by 1 hour in manufacturing in the 1964-99 period, from 40.7 to 41.7 hours.
Among service-producing industries, the biggest decline by far in weekly hours was in retail trade, from 37 hours in 1964 to 29 hours in 1999. Finance, insurance, and real estate had the smallest drop in hours, from 37.3 to 36.2 hours.
This information is from the BLS Current Employment Statistics program. For each industry, average weekly hours is computed by dividing the sum of reported paid hours by the total number of production or nonsupervisory workers in the industry. Changes in average weekly hours in an industry can be due to various reasons; for example, there could be a shift in an industry to employing more part-time workers. Learn more about average weekly hours in "On the decline in average weekly hours worked" by Katie Kirkland, Monthly Labor Review, July 2000.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Changes in average weekly hours, 1964-99 at https://www.bls.gov/opub/ted/2000/sept/wk1/art02.htm (visited September 29, 2022).