Shasti Poorthi is celebrated on completion of 60 years of age of the male. This term is derived from Sanskrit in which Shashti means sixty; abda–year; poorthi-completion. It marks completion of half the years of one's lifetime as in Hinduism, 120 years is considered the life span of a human being. The sixtieth year in one’s life is a significant milestone, memorable turning point, a touching reminder of the rich, mellowed life that would unfold in the years to come. In fact, the Hindu calendar has 60 years (named Prabhava, Vibhava, etc.) that repeat themselves after every 60 years in a sequence. Shashti poorthi marks the completion of one such cycle. For example, a person born in the year Pramodootha and has lived for 60 years will have seen all the 60 years in the calendar. This milestone marks celebration and gratitude for life given by God. So once his birthday arrives in Pramodootha year, he performs his Shashti poorthi. In recent days, children started doing this ritual to their parents, just as their parents performed all of their rituals in their childhood.

The veda says "Janmaabde, Janmamaasecha Swajanmadivase tathaa, Janmarshe chaiva kartavyaa shanti rugrarathaahvayaa, Devaalaye nadeeteere swagruhe vaa shubhasthale". The sages and the rishis of lore have acknowledged the sanctity of the sixtieth year in one’s life and have drawn out elaborate rituals to mark this special event. They looked at it as rebirth and suggested the repetition of those rituals performed at one’s birth. Hence this celebration at this point of life is a sacred part of the hallowed Vedic culture. The Shastipoorthi Shanti should be performed in the sixty first year and in the same month and day of birth according to the Indian Zodiac. This is considered to be the best option. In case it is not possible to time it exactly on the same day, allowance is given to perform it on a convenient day during and before the completion of sixtieth year. The choice of the place to carry out this tradition could be a pilgrim town, a temple, a river bank or even one's residence. As part of the celebrations the couple's children perform their parents' second wedding. This is reason for a grand family reunion to incorporate an important event in the couple's married life.