Since 1977, the percentage of kindergartners enrolled in full-day (in contrast to half-day) programs has nearly tripled, increasing from 28 to 76 percent between 1977 and 2012.
Overall, children who spend time in full-day kindergarten programs are more likely than children who spend time in half-day kindergarten programs to devote time every day to reading, mathematics, and social studies.  Full-day kindergarten allows teachers more time to promote formal and informal learning, reduces the number of transitions in a child’s day, and allows children to get used to a schedule similar to that which they will have in first grade. In the short-term, children attending full-day kindergarten programs tend to do better in school than do children attending half-day kindergarten programs, and show stronger academic gains in kindergarten.,, Full-day kindergarten programs may be especially beneficial for children from low-income families, especially if class size remains small. However, a study using nationally representative data found little evidence that full-day programs are particularly beneficial for poor as opposed to non-poor children.
Research is inconclusive on longer-term impacts. A nationally representative study, using data from the Early Childhood Longitudinal Survey-Kindergarten Cohort, found that academic gains of full-day programs had largely disappeared by the end of first grade. However, another study found that children in full-day kindergarten programs scored higher on standardized math and reading tests through the second grade. Additionally, some research finds that children in full-day programs have more behavior problems than do children in half-day programs, with differences especially large when comparing half-day programs that met in the afternoon with full-day programs. A recent meta-analysis found that kindergarteners in full-day programs were more likely to have good attendance, self-confidence, and the ability to work and play with others, but less likely to have a positive attitude towards school. 
Since 1977, the percentage of kindergartners enrolled in full-day rather than half-day programs has more than doubled, increasing from 28 percent of all kindergartners in 1977 to 76 percent of all kindergartners in 2012. Increases were especially steep between 1996 and 1998, and between 2002 and 2006. (Figure 1)
Differences by Race and Hispanic Origin
Black kindergartners are much more likely than other kindergartners to be enrolled in full-day programs. In 2012, 87 percent of black kindergartners were in full-day programs, compared with 68 percent of Asian or Pacific Islander, 74 percent of Hispanic, and 75 percent of white kindergartners. Eighty-five percent of American Indian kindergartners were enrolled in full-day programs. (Figure 2)
Differences by Region
Kindergartners in the South and Midwest are more likely than those in the West to be enrolled in a full-day program (83 and 80 percent, compared with 64 percent, respectively, in 2012). Kindergartners in the Northeast fell in the middle, at 71 percent in 2012. (Figure 3) However, differences between regions have been decreasing. (Appendix 1)
Differences by Family Income
In 2012, kindergarteners in low-income families and those in higher-income families were equally likely to be in full-day programs. (Appendix 1)
Differences by Type of School
In 2012, kindergarteners in public and private schools were equally likely to be in full-day programs. Prior to 2004, however, students in private schools were more likely to be in full-day programs. (Appendix 1)
State and Local Estimates
The Education Commission of the States maintains an on-line database of information on states’ policies (statutory and finance) affecting kindergarten.
- Preschool and Prekindergarten
- Child Care
- School Readiness
- Kindergartners' Social Interaction Skills (archived)
- Public Schools with Pre-K and Special Education Pre-K Programs (archived)
This indicator includes those kindergartners, ages four to six, who are enrolled in a full-day kindergarten program, either public or private.
Data for 1994-2012: Child Trends' original analyses of data from the Current Population Survey, October Supplement.
Data for 1977-1992: Wirt, J., Choy, S., Rooney, P., Provasnik, S., Sen, A., and Tobin, R. (2004). The Condition of Education 2004 (NCES 2004-077). U.S. Department of Education, National Center for Education Statistics. Washington, DC: U.S. Government Printing Office. Available online at: http://nces.ed.gov/programs/coe/2004/pdf/03_2004.pdf
Raw Data Source
Current Population Survey, October Supplement
Appendix 1 - Percentage of Kindergarteners, Ages Four to Six, Enrolled in Full-day Kindergarten: Selected Years, 1977-2012
|Asian or Pacific Islander||-||-||-||-||-||-||56.6||49.7||60.4||66.5||67.9||60.2||62.0||63.1||60.1||69.5||68.4|
|American Indian or Alaska Native||-||-||-||-||-||-||75.9||60.3||68.0||76.0||49.7||86.8||86.3||67.5||62.0||74.0||85.1|
|Less than a high school degree||-||-||-||-||-||-||52.1||53.4||64.8||69.3||76.3||75.1||73.5||74.9||71.9||84.6||74.7|
|High school degree/equivalent||-||-||-||-||-||-||48.5||51.9||60.2||73.8||71.7||74.2||74.8||77.6||73.3||77.1||73.1|
|Some college/technical vocational degree||-||-||-||-||-||-||45.5||51.3||60.3||70.0||74.2||71.6||75.1||76.4||73.2||78.4||79.0|
|Bachelor's degree or more||-||-||-||-||-||-||46.3||48.1||54.1||65.6||65.9||67.6||66.9||68.8||71.5||73.3||75.4|
|Two native-born parents||-||-||-||-||-||-||47.1||52.3||60.4||71.1||72.7||71.8||72.5||74.3||74.0||76.8||78.1|
|Native-born with at least one foreign-born parent||-||-||-||-||-||-||58.5||46.7||59.2||65.9||69.5||68.9||71.5||73.0||68.7||77.9||69.2|
|Foreign-born with at least one foreign-born parent||-||-||-||-||-||-||39.6||40.2||58.8||66.9||67.0||77.2||60.4||68.6||78.1||73.4||82.0|
|Less than $15,000||-||-||-||-||-||-||53.2||61.5||72.4||76.1||77.0||79.5||78.1||80.1||78.5||80.7||78.9|
|Type of School|
“-“ data not available.
Sources: Data for 1977-1992: Wirt, J., Choy, S., Rooney, P., Provasnik, S., Sen, A., and Tobin, R. (2004). The Condition of Education 2004 (NCES 2004-077). U.S. Department of Education, National Center for Education Statistics. Washington, DC: U.S. Government Printing Office. Data for 1994-2012: Child Trends' original analyses of data from the Current Population Survey October Supplement.
Walston, J. T., and West, J. (2004). Full-day and half-day kindergarten in the United States: Findings from the Early Childhood Longitudinal Study, Kindergarten Class 1998-99. U.S. Department of Education, National Center for Education Statistics (NCES 2004–078). Washington, DC: U.S. Government Printing Office. Available at: http://nces.ed.gov/pubs2004/2004078.pdf
Finn, J. D. & Pannozzo, G. M. (2004). Classroom organization and student behavior in kindergarten. Journal of Educational Research, 98(2), 79-92.
Kauerz, K.. (2005). Op cit.
Guarino, C. M., Hamilton, L. S., Lockwood, J. R., & Rathbun, A. H. (2006). Teacher qualifications, instructional practices, and reading and mathematics gains of kindergartners (NCES 2006-031). U.S. Department of Education. Washington, DC: National Center for Education Statistics. Available at: http://nces.ed.gov/pubs2006/2006031.pdf.
 Zvoch, K., Reynolds, R. E., & Parker, R. P. (2008). Full-day kindergarten and student literacy growth: Does a lengthened school day make a difference? Early Childhood Research Quarterly, 23(1), 94-107.
Cannon, J. S., Jacknowitz, A., & Painter, G. (2006). Is full better than half? Examining the longitudinal effects of full-day kindergarten attendance. Journal of Policy Analysis and Management, 25(2), 299-321.
Gullo, D. F. (2000). The long term educational effects of half-day vs full-day kindergarten. Early Child Development and Care, 160(1), 17-24.
Finn, J. D. & Pannozzo, G. M. (2004). Op cit.
Cooper, H., Batts, A., Patall, E. A., & Dent, A. L. (2010). Effects of full-day kindergarten on academic achievement and social development. Review of Educational Research, 80(1), 54-70.
Hispanics may be of any race. Estimates for whites and blacks do not include Hispanics.
Child Trends. (2013). Full-day kindergarten. Available at: http://www.childtrends.org/?indicators=full-day-kindergarten
Last updated: August 2013