The Feast Day of Saint David of Wales is celebrated on March 1st. Saint David, also known as Dewi Sant, was a Welsh bishop and patron saint of Wales. He founded many monasteries throughout Wales and played a significant role in spreading Christianity throughout the country. On his feast day, it is traditional to wear a daffodil, which is the national flower of Wales. Many people attend church services, and there are often parades and other celebrations in Welsh communities around the world.