Happy Mid-Autumn Festival! (traditional: 中秋節, simplified: 中秋节) . Mid-Autumn Festival (aka Moon Festival) is one of the most important holidays in the Chinese calendar and is held on the 15th day of the 8th month in the Chinese calendar. This year that corresponds to October 3rd! Traditionally, you eat moon cakes and give moon cakes to your friends and family to share. Tonight look up and you will see the moon at its roundest and fullest. A short video about the goddess who lives on the moon.