A study was conducted to determine how the length of the school day affects the academic achievement of kindergarten children who are deficient in readiness skill development (low performance in auditory memory, rhyming, letter recognition, visual matching, school language and listening, and quantitative language as measured by the Metropolitan Readiness Test). Subjects were 40 students who attended a regular half-session kindergarten program and 30 students screened as severely deficient in readiness skill development who attend an extended day program. At the end of six months, the students were given the Metropolitan Readiness test, the results of which indicated that the full-day participants had achieved the level of readiness skill development of the half-day participants. (HTH)