Shani is one of the nine primary celestial beings in Hindu astrology (that is, Vedic astrology).
Shani is embodied in the planet Saturn. Shani is the Lord of Saturday.
He is Tamas in nature and represents learning the hard way, Career and Longevity.
The origin of word Shani comes from the following: Shanaye Kramati Sa: i.e. the one who moves slowly.
Saturn takes about 30 years to revolve around the Sun, thus it moves slowly compared to other planets.
Shani is actually a demi-god and is a son of Surya (the Hindu Sun God) and his wife Chhaya.
It is said that when he opened his eyes as a baby for the very first time, the sun went into an eclipse, which clearly denotes the impact of Shani on astrological charts (horoscope).
He is depicted dark in colour, clothed in black; holding a sword, arrows and two daggers and variously mounted on a black crow or a raven.
He is depicted at other times as ugly, old, lame and having long hair, teeth and nails.
He presides over 'Shani-war' or Saturday.
Sani Bhagavan waiting to aspect Nala, noticed that he had not washed the back portion of his feet, while preparing for his prayers.
Deciding this was the opportune time, he aspected Nala.
Because of this, Nala lost his composure and lost his kingdom to Pudkaran in a game of dice and sent his children to their uncle's house.
Nala departed to the forest with his wife Damayanti.
Saneeswaran created trouble even there and made Nala desert his wife in the forest.
The snake Karkotagan bit Nala, making him lose his stature (was made to look ugly).
He took on the job of a charioteer with king Irudhupannan.
Damayanti, in the meantime reached the kingdom of her father, and arranged a Swayamvara to locate Nala.
Damyanti identified Nala, the charioteer as her husband. Thanks to a boon from Karkodagan, Nala regained his old form.
In spite of being back with his wife, Nala feeling very disturbed, sought the solace of sage Bharadwaja and on his advice reached Thirunallar.
He bathed in the Brahma Thirtham of the temple, and when he entered the sanctum sanctorum of the temple, Saneeswaran departed from him.
The presiding deities are Dharbaranyeswarar (Swaymbumurti) and his consort Bogamartha Poon Mulayal.
Saneeswaran resides in each Rasi for a period of 2 1/2 years.
When Saneeswaran resides in the 12th, 1st and 2nd house, it is 7 1/2 Naatu Sani ;
when in the 4th house, it is Arthashtama Sani;
when in the 8th house, it is Ashtama Sani.
During these periods, he troubles the native.
Problems from Govt., peers, wife, children, slowdown in business, loss of property, leprosy are caused by transit of Sani.
In a person's life, 7 1/2 Naatu Sani aspects thrice, the first called Mangu Sani, the second called Pongu Sani and the third called Marana Sani.
Saneeswaran is reputed to be both, a giver and destroyer.
A person who prays to Saneeswaran will be blessed with not only riddance from the problems and worries faced, but a life that one desires. T
he sthalam of Sani Bhagavan is Thirunallaru, which is located 3kms from Karaikal, enroute to Peralam.
His wives are Neela Devi and Manga Devi.
He is the Lord of Maharam and Kumba Rasis and faces the West direction.
The Adi Devatha is Yaman and the Prathyathi Devatha is Prajapathi.
His colour is black;
his vahana the crow;
the grain associated with him is gingelley;
the flower - vanni and black kuvalai;
fabric - black cloth;
gem - neelam (blue saphire);
food - rice mixed with gingelle.