With an overview how Moodle plugin works, this paper aims to focus on those areas where open source software impact has on learning management system software which is distributed for free. One of the essential goal of this project is to develop plugin tool for Moodle, which aid users by providing less interaction time while adjusting date related tasks mainly with courses and assignments, which currently in the Moodle system is accomplished by a lot of steps. The project concentrated on two application functions, namely assignment_daterollover and course_daterollover. These two application plugin features in Moodle learning environment allows instructors to automatically update all date items in their course at the beginning of each semester. Date adjustments can easily be made to each assignments in a course through one centralized screen, rather than having to go into each individual learning activity. The two plugin tool options are one which will change the course start date by which all assignments can be simultaneously set forward by a specified number of days which is called course_daterollover and the other option is to adjust individual assignment items within a course which is called assignment_daterollover. Through the methods, the number of steps (clicks) has been counted and compared with the existing date adjustment method in Moodle for course and assignments, to evaluate and identity UI limitations Heuristic evaluation method is used. The plugin is implemented using block-plugin, because of its appearance to simply reside the content on the right or left side of each main course page, which also gives users the right to turn it on or off if they don't want to use it. In addition, the tool can be used as an option associated with the existing Moodle date adjustment system from the point of view of having a different design. The result is a user-friendly plugin tool interface for the stated two purposes which have less number of clicks than the Moodle date adjustment system for courses and assignments. The plugin tool can be used by anyone since it has been published on Github. As a conclusion, Moodle with its cost-effectiveness can serve a lot of users around the world.