The recent push among policymakers and activists for a longer school day is just the latest manifestation of the "more is better" approach to school reform. But more time in school is not necessarily proven to generate better results. Successful schools with longer days have other characteristics that count toward success but that are not as hard to replicate. Moreover, without curricular or instructional reform, failing schools with longer school days will simply fail their students for several more hours per week. Key points in this "On the Issues" include: (1) Adopting longer school days nationwide could cost as much as $70 billion per year--enough to double the pay of the best third of teachers; (2) There is evidence that a longer day does not boost performance; at best, a longer day produces only modest improvements; and (3) Schools would be wiser to make use of the time they already have, much of it currently wasted on noninstructional activities. (Contains 3 notes.)