Shani Jayanti, also known as Shani Amavasya, is observed as the birth anniversary of Lord Shani. It is believed that Lord Shani, the son of Lord Suryadev, rules planet Saturn and the weekday Saturday.
According to North Indian Purnimant calendar, Shani Jayanti is observed on Amavasya Tithi in Jyeshtha month. According to South Indian Amavasyant calendar, Shani Jayanti is observed on Amavasya Tithi in Vaishakha month. Only the name of Lunar month differs, but in both type of calendars Shani Jayanti falls on the same day.
Shani Jayanti coincides with Vat Savitri Vrat, which is also observed on Jyeshtha Amavasya in most North Indian states. Devotees observe fast on Shani Jayanti to appease Lord Shani and visit Shani temples to seek his blessing. Lord Shani believes in fair justice and if worshipped with full devotion will bless His devotee with prosperity and fortune. People, without the blessings of Lord Shani, work hard for their entire life without getting any reward.
The day of Shani Jayanti is highly auspicious to perform Hawan, Homam and Yagya to please Lord Shani. Shani Tailabhishekam and Shani Shanti Puja are the most significant rituals performed during Shani Jayanti. These rituals are performed to reduce the effect of Shani Dosha, which is popularly referred as Sade Sati, in the Horoscope.
Shanishchara Jayanti and Sani Jayanthi are the other names of Shani Jayanti.