Worked on the rails/rails repository to address correctness and consistency in time zone data, focusing on backend development using Ruby and Ruby on Rails. Delivered a targeted bug fix that updated time zone identifiers for Kyiv and Yangon, replacing outdated names with current IANA tz conventions. This change improved data consistency and localization accuracy across systems relying on Rails time zone data, ensuring that logs, reports, and user-facing features reflect accurate geographical information. The work demonstrated disciplined change management, with a small, well-documented update linked to a specific commit, providing clear traceability and minimizing risk to the broader codebase.