Among the Navahos there are no fixed dates for ceremonies or holidays as among the Pueblos.  Navaho ceremonies are held particularly on occasions of sickness and either consist of a prayer for the sick person's recovery or a celebration after recovery.  The old medicine men are engaged by the family of the sick person and the wealthiest of the Indians engage the most famous and proficient medicine men and singers or chanters.  This is one of the most famous medicine men, being unusually well versed in the religious myths of the tribe.