During February 2025, [Developer Name] developed the foundational Invoice Management System for the KShiMin/Hospital_Management_System repository. They designed and implemented a modular Invoice class in Java, incorporating object-oriented principles to manage invoice attributes and lifecycle methods. The work included a main demo application to create, manage, and print invoices, providing a basic workflow for billing and invoice previews. Although no bugs were addressed during this period, the code established a clear path for future enhancements such as persistence and reporting. The focus on Java development and testing ensured a maintainable structure, laying essential groundwork for future invoicing features.