During February 2025, contributed to the flutter/flutter repository by enhancing the CupertinoDatePicker widget to better support the Korean locale. Focused on aligning the time display format with local conventions, the work involved updating the order to present AM/PM before hour and minute, addressing a longstanding localization issue. Utilized Dart and Flutter, applying localization and widget testing skills to ensure accuracy and prevent regressions. Automated tests were added to validate the new time order, and a targeted bug fix resolved an existing datetime order problem. This approach improved the user experience for Korean users and strengthened overall localization quality assurance.