Many learning opportunities in subjects not widely available to students a generation ago have swelled curriculum offerings, and, in an effort to enrich its programs, larger school districts have been prompted to move toward an "extended school year" as a solution. This document reports the results of a study made to ascertain if the school year has, in actuality, been lengthened in such districts. Information concerning the length of the school day (including lunch periods) was gathered from the 575 largest school systems. Analysis of the data on a system-by-system basis revealed that the median school day in systems enrolling 12,000 or more students was shorter in 1970-71 than it was in 1964-65. Survey results are provided in tabular form according to school district enrollment size and by grade level. (Author/MLF)