St. Gangolf's Day is celebrated on April 28th in honor of Saint Gangolf, a Christian martyr from the 8th century. The day is particularly recognized in parts of Germany, where local traditions and festivities take place. On this day, communities often hold special church services and processions to commemorate the saint's life and contributions. In some regions, people may also participate in local fairs or cultural events, reflecting the significance of St. Gangolf in their heritage and religious practices.