Scheduling conflicts among student organization activities are a recurring problem that requires an efficient management solution. This research implements a web-based scheduling application using a three-tier architecture, built with the PHP programming language and a MySQL database. A Greedy algorithm is applied to automatically arrange activity schedules based on priority level, in which activities with lower priority are automatically shifted to the next available time slot whenever a conflict occurs. A key feature of the system is a three-hour buffer review period that gives the admin time to review the results of schedule shifting before the schedule is finalized, supported by an auto-commit mechanism that takes effect if no response is given within that period. Functional testing (blackbox testing) shows that all features perform in accordance with their specifications, while User Acceptance Testing (UAT) yielded an average score of 4.8 out of 5.0 from respondents who are student organization administrators. These results indicate that the system is able to provide a practical solution for avoiding schedule conflicts while also delivering information transparency through a public calendar accessible without authentication.