Thirteenth day of Hindu calendar is called Trayodashi Tithi. Fortnight Trayodashi (Trayodashi Amavasya) that falls on Saturday is called as Shani Trayodashi.
Shani dev is considered as Lord of Saturday. It is a very auspicious day to perform puja, yagna or Tailabhishekam with gingelly oil to Lord Shani.
He is the son of Lord Surya Bhagavan and Chaya. Shani is also called as Chayaputra.
Lord Shani is personified in the planet Shani or Saturn and devotees believe he removes obstacles.
Also Read about Shani Jayanti & find 2017 Shani Jayanti Date.
Shani Jayanti Mantra
Shani Dhyan Mantra
Nilanjana Samabhasam Ravi Putram Yamagrajam Chaya Mrttanda
Sambhutam Tam Namami Shanai Shwaram
Shani Gayatri Mantra
Aum Sanaischaraya Vidmahe,
Tanno Manda Prachodayat.
Om Sham Shanaischaryaye Namah!
नीलांजन समाभासं रविपुत्रं
संभूतं तन्नमामि शनैश्चरम।।
ओं शनैश्चराय विद्महे
नीलदेहाय धीमहि। तन्नो शनि