Loy Krathong is an annual Thai festival celebrated throughout southwestern Thailand on the evening of the full moon of the 12th month in the traditional Thai lunar calendar, usually falling in November. It originates from the tradition of making Krathong, small floats made of banana leaves and flowers, which are floated in rivers while carrying candles to honor Buddha and symbolize letting go of bad feelings. Modern Krathongs are often made of bread and disintegrate after a few days. On the same night, the Yi Peng festival is celebrated in northern Thailand, where sky lanterns shaped from rice paper and with candles are launched into the air, again symbolizing releasing bad feelings.