In response to California Legislation that would change the cut-off for the minimum 5-year entrance age from December 2 to September 1, this paper reviews the literature discussing the appropriate age for beginning school. The review includes a brief history of kindergarten and its place in California law; discusses the possible impact of the proposed legislation upon California's demographic issues; and summarizes major theories of childhood development and relates them to kindergarten readiness. The review groups and characterizes the literature according to the effect of school entrance age upon scholastic achievement. The literature's consideration of other factors such as gender, socioeconomic status, preschool attendance, and influences of teachers' perceptions and methods is reported. The review also considers trends evident in the literature, such as an increasingly academic kindergarten curriculum, increasing emphasis on testing, and growing parental sentiment for delaying school entry. The review lists California programs such as the CalWORKS welfare program, the Class Size Reduction Initiative, year-round schools, the Standardized Testing and Reporting Program, and universal publicly funded preschool as programs that would be affected by altering the entrance age. Two appendices list characteristics of kindergarten admission in other states and summarize specific studies. (Contains 155 references.) (AB)