Because there was a gap in the literature about the nuances of a four-day school week, it was not known if there was a difference in performance indicators in a school calendar with Monday off compared to a school calendar with Friday off. The purpose of this comparative descriptive study was to determine if there was a difference in achievement for a Colorado school district that changed the four-day calendar from Monday off to a Friday off in 2005. This quantitative study provided a before and after baseline to determine if one scheduling approach affected attendance and student achievement over the choice of another. Attendance data were available for the entire school district. Student achievement data was available for third grade through tenth grade. The statistical test for attendance was a population proportion. The statistical test for student achievement was a paired "t" test. The theoretical foundation was based on Marzano's model where "time" was the most important factor for learning. However, results of the current study indicated a decline in attendance and a statistically significant increase in student achievement. The implication was that a community focus on learning could have been what affected achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]