The purpose of this study was to analyze demographic and school data, as well as data on the perceptions of teachers regarding the impact that a modified year-round school calendar has on student achievement, student behavior, and teacher efficacy. Prior research and literature examined the impact of year-round school calendars on student achievement and student behavior; however, there was a limited amount of research on the perceptions of teachers regarding the school calendar and the impact that the school calendar has on teacher efficacy. A thirty-seven item researcher-developed questionnaire was utilized for the purpose of this study. The data for this study were obtained from 106 teachers from public schools within districts in the state of North Carolina that employ both traditional school calendars and year-round type calendars. Demographic data disclosed that these respondents were relatively experienced and that the majority worked in schools with high concentrations of students in poverty. The results did not disclose a significant relationship between teacher perceptions of the school calendar and teacher efficacy. However, a strong positive correlation was found between teacher perceptions of year-round school calendars and improved student achievement. Similarly, the study revealed a significant relationship between teacher perceptions of year-round school calendars and positive student behavior. A multiple regression analysis determined that grade-level taught served as a negative predictor of teacher perceptions regarding a modified year-round school calendar's impact on student achievement, student behavior, and teacher efficacy. These findings yielded useful recommendations for policy and practice. Additionally, this study served as a vehicle for continued research into matters of year-round education. Finally, in light of the researcher's interest in a research-based discourse of year-round education in Mississippi, the location where he lives and practices, the study offered a spring-board for exploration of the potential benefits of year-round education in Mississippi. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]