Women are more likely than men to work part-time — that is, fewer than 35 hours per week, according to data released October 4 by the U.S. Department of Labor's Bureau of Labor Statistics.
Women who worked part-time made up one-fourth of all female wage and salary workers in 2005. In contrast, just 11 percent of men in wage and salary jobs worked part-time. About two-thirds of female wage and salary workers worked 40 hours or more, while 86 percent of male workers worked at least 40 hours per week.
This data is from the Current Population Survey. For more information see "Highlights of Women’s Earnings in 2005," BLS Report 995 (PDF 290K).