Navajo weaving Yei bi Chai dance. One of the major ceremonies of the Navajo is the nine-day Night Chant or Yei'bi'chei dance. It is only held during the winter months and is usually attended by everyone from miles around. It is during this ceremony that boys and girls receive their initiation into the rituals of Navajo religion. The main purpose of the ceremonies is to bring harmony and balance to the people and realign them with nature for their health and well being.