This quantitative study was conducted to determine whether a significant difference existed between secondary schools that observed the four-day school calendar and the five-day school calendar when comparing secondary schools’ Annual Progress Report (APR) scores of academic achievement levels and attendance levels, as well as the secondary school teachers’ perception of school climate. Five of the participating schools observed the four-day school week and five schools observed the five-day school week. The first portion of the study consisted of taking the average APR scores for attendance from both the four-day and the five-day schools and comparing them in an independent t-Test. The second portion of the study consisted of taking the average APR scores for academic achievement levels and comparing them in an independent t-Test. The final step in the study was to determine teachers’ perceptions of school climate by administering the Organizational Climate Index, which was created by Hoy, Smith, and Sweetland (2002). The school climate portion of the study consisted of teacher participants from the 10 participating schools. This survey was administered to 70 teacher participants using Survey Monkey (Survey Monkey, 2018); 35 teachers were employed at a four-day secondary school, and 35 were employed at a five-day secondary school. The responses were scored and an average score was found for the both the four-day teacher responses and the five-day teacher responses. The scores were compared in an independent t-Test. The results of the t-Test in each case did not provide proof that a significant difference existed between the four-day school week and the five-day school week.