Lịch vạn niên xem ngày tốt xấu (FOREIGN CALENDARis a Lunar Calendar application designed to help users determine good and bad days based on the lunar/positive calendar, seamlessly integrated with the default Android calendar. The app offers various features such as an intuitive Lunar Calendar Block on the main screen, easy navigation between date views, conversion between lunar and solar calendars, and daily weather updates by location.

Additionally, users can benefit from a Feng Shui Compass providing insights into home decor according to PHONG THUY, information on daily departure directions, fate details including can chi and five elements, traditional vows for Vietnamese holidays, integration with the Android calendar for event creation and synchronization, biological rhythm tracking, and a Ruler Lo Ban for measuring furniture and building sizes based on traditional perspectives.