There has been a marked increase over the past three decades in the share of married couples in which both husband and wife work 35 or more hours a week.
In 1969, both spouses worked full-time in about 24 percent of married couples in which both spouses were age 25 to 54 years. By 1998, this figure had risen to 43 percent. The increase was more dramatic among couples with children under age 6. In 1998, fully 31 percent of such couples had both spouses at work full-time, up from 13 percent in 1969.
One of the results of this increase has been an extension in the total time spent at work by the average married couple. In 1998, married couples spent, on average, 14 more hours working per week than they did in 1969. Once again, married couples with children under 6 experienced the largest increase. Their combined hours rose from 52.3 per week in 1969 to 68.3 in 1998.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Full-time working couples more common at https://www.bls.gov/opub/ted/1999/nov/wk1/art02.htm (visited January 28, 2023).