Normal age to perform Upanayanam: between 7-15yrs, generally odd running year is chosen. If performed after the age of 15 years, then no need to stick to this rule. Best period for performing the ritual is during Uttarayan, i.e. from mid January till mid July. During Dakshinayana, it is advisable to avoid performing Upanayanam. Also, Sama Veda followers must avoid performing Upanayanam during the time when Mars is set (Kuja Asthamanam), Rig Veda followers should avoid during Jupiter’s setting (Guru Asthamanam) and Yajur Vedi’s should avoid during Venus setting period (Shukra Asthamanam). On the day of Muhurtham, the selected house should be clean and without any malefics. This is must for performing the Brahmadesam. Due to paucity of time, unavailability of halls and economical considerations, nowadays, Udaka Shanthi, Nandhi and Upanayanam/Brahmmobadesam are performed in a single day.
According to the Manusmrti which specifies the following ages for the initiation ceremony to take place:
In the eighth year after conception, (i.e. at the age of 7) one should perform the initiation of sacred thread) of a Brahmin, in the eleventh year after conception for a Kshatriya and in the twelfth year that of a Vaisya. (Manu Smruthi II.36).
The Hindu Dharma believes that marriage is a sacred bond between a man and a woman. A lifelong commitment where both partners take vows to fullfill each other’s wishes and keep them happy forever. Vivaham is precisely that ceremony performed that marriage ceremony performed by the priest.