In January 2025, Nick Moller developed a Leap Year Calculation feature for the JoyOfCodingPDX/KatasWinter2025 repository, introducing a LeapYears class with constructor-based year initialization and comprehensive leap-year logic. He applied Core Java and unit testing to ensure correctness, building a dedicated test suite and iteratively refining the implementation through four commits that reflected a test-driven, collaborative approach. Alongside the feature, Nick addressed documentation accuracy by updating ICanEditThisRepo.txt, replacing outdated terminology. His work delivered a reliable date-calculation capability, improved code quality through refactoring and test coverage, and contributed to a more accurate and maintainable onboarding experience for users.