Worked on the DEFRA/water-abstraction-system repository to deliver the Return Period Presenter Enhancement for User Notifications. Refactored the returns period presenter and its associated tests using JavaScript, focusing on front end development and robust testing practices. Updated the presenter logic to ensure consistent and accurate formatting of return period data, addressing potential issues with user notification displays. Expanded test coverage to include a wide range of date scenarios, improving reliability and reducing the risk of incorrect information being shown to users. The work enhanced maintainability of both the presenter and its tests, supporting clearer and more dependable user notifications going forward.