Four-day school week schedules are being adopted with increasing frequency, particularly in rural areas. In this paper, we consider the academic implications of students in Oregon attending a four-day school week for the first time when they enter high school. We find 11th grade math achievement in 0.09 standard deviations lower among four-day school week students, with significant impacts driven by four-day school week students in non-rural settings. We also find a greater number of four-day school week students being classified as chronically absent. Finally, we find reductions in on-time graduation among four-day school week students compared to five-day students.