Loy Krathong happens on the first full moon day of November. Thai people buy or make a krathong, which is like a small boat made of banana tree and banana leaves, with flowers and a candle in the middle. At night the krathongs are set adrift on a nearby river or pond, as an offering to the spirit of the water to wash away the sins. According to an ancient proverb, when a boy and a girl float a krathong together, they will be lovers either in this life or the next.