Arizona's public school system is administered by the Arizona Department of Education and is notable for its early academic calendar, with most districts beginning instruction in late July β among the earliest start dates in the nation. This early start is driven in part by the state's extreme summer heat, which makes late-summer outdoor activities difficult, and by the desire to complete the first semester before the winter holiday break. The academic year typically concludes in late May, giving students a longer summer break in the cooler months. Arizona requires 180 instructional days and is known for its robust school choice landscape, including one of the largest charter school sectors in the country and a broad education savings account (ESA) program that allows families to use public funds for private schooling. Many Arizona districts incorporate a fall break in October, a scheduling feature less common in other states, which helps break up the long stretch between the start of school and Thanksgiving. The Phoenix metropolitan area encompasses dozens of independent school districts with varying calendars, so families should confirm specific dates with their local district. Arizona administers the AzSCI and AzM2 state assessments in spring to measure student achievement in science and mathematics.