Shani Jayanti is the birthday of Lord Shani or Sani. Shani bhagwanis one of the Navagrahas (Nine primary celestial deities). Shani Jayanti or Saneeshwara Jayanti observed on Amavasya (No Moon day) in Vaishakha masam (Vaishakha Amavasya). In 2012, Shani Jayanthi falls on May 20, Sunday.
In Hinduism, Sani is the deity of Shanivar. Shani bhagwan is also called as Shaneeswaran, Sani dev, Sanischara bhagwan or Chaya Putra.
Rituals and Customs of Shani Jayanti:
As Shani Dosham (bad effects from Lord Shanis position in ones birth chart) is considered as an important feature in ones future aspects, Shani Puja is an auspicious ritual for Hindu astrology believers.
Those who have Sade sathi (a long period of bad effects from Lord Shani) in their horoscope, observe Shani Yagna or Shani homa on Shani Jayanti day. People believe that Shani worship on Shani Jayanthi day pacifies Sani (happens Sani Shanti).
On the day of Sani Jayanti, devotees perform Lord Ganesha Puja (Ganapati Puja), Lord Hanuman Puja, Lord Venkateshwara (Balaji) Puja to pacify Shani. It is believed that the devotees of Lord Hanuman are free from the Shanis bad effects on their lives.