To get blessings from Lord Shiva so many Poojas are being done. In these Poojas, Prathosam is a notable one.
Lord Shiva directed the disciple, Anukka Thondar Sundarar to bring the Alagala Poison. Anukka Thondar Sundarar was a replica of Lord Shiva who gathered the poison and gave it to Lord Shiva. As the poison would cause havoc, Lord Shiva swallowed it. Lord Shiva is embodiment of the entire universe. This day is called Ekadesi. In these days, Devas started penance and worshipped Lord Shiva and got happiness. The day after Ekadesi is called Duvadesi. In this day,Devas started penance and got happiness. The day after Duvadesi is called Thriyodesi. In this day, Lord Shiva taking Thamarugam and Thrisoolam in His hands and danced on the head of Lord Nandhi in front of the Goddess Uma, Rishi, Saint and 33 crores of Devas and got blessings. Lord Shiva danced in between day and night time before the sun set at 4.30 PM to 6 P.M.. This dance is called Santhya Nirutham. Lord Shiva swallowed the Aalagala poison and danced in Saturday Thryiodesi. The Puranas says that the Prathosam coming in Saturdays is an important one.
As Lord Shiva danced on the head of Lord Nandhi,Nandhi takes place in Prathosam. When the Lord Shiva swallowed the Aalagala poison, Lord Nandhi inspired the speed of Aalagala poison and His tongue became bluish. Special poojas are being followed in Prathosa time, as well as Lord Shiva and Lord Nandhi in this temple.
Through the head of Lord Nandhi,We will worship the Lord Shiva, wearing Grass Garland to Lord Nandhi switching on 13 ghee lamps, raw rice mixing jaggery and submit it to Lord Nandhi.
Usually, it is different from ordinary days and Prathosam, the rotation of temple. This is called "Sundhara Valam" At this end of rotation we will do roam ourselves. In Prathosam special poojas are followed in this temple.
Prathosam prayer is equal to Deva Dharshnam. It is very powerful for us for the Prathosa pooja.