A new national study provides some of the strongest evidence to date to support what many educators and parents of young children already believe, children learn more in full-day kindergarten programs than they do in half-day programs. The findings are based on federal data from a nationally representative sample of 8,000 children in public kindergarten programs. The results show that, on average, the learning gains that pupils make in full-day programs translate to about a month of additional schooling over the course of a school year. Disagreement is widespread over whether any educational value full-day programs convey is worth the added expense.