Upanayana is one of the most important ceremonies of Hindus. It is also called the sacred treaty ceremony because the boy is invested with the sacred thread which alone entitles him to be recognized as an Aryan.
Before this ceremony and investiture with the sacred thread, a boy of any of the three higher castes is not recognized as belonging to his proper caste but a Sudra. Upanayanam takes place between the ages of 7 to 10.
The day of the ceremony must fall in one of the five auspicious months in which the sun is moving northwards towards the Ecliptic. The time of the day must be between 6 AM to noon.
The sacred thread is consecrated by Brahmins before girding the boy. Verses of the Vedas are chanted and Gayatri mantra is whispered three times into the boy’s ears. At the end of the ceremony all elders bless the boy.