Sani Trayodasi, also spelt s Sani Triodasi, is an auspicious day to worship Lord Sani. In November 2009, Shani Trayodasi date is November 14. This trayodasi falls in Kartika masam as per Telugu, Kannada, Marathi and Gujarati calendars and in Margashirsha month as per other North Indian Panchang. Triodasi which falls on Sanivar is considered as Sani Trayodasi.
Devotees and believers of Shani dosham perform Shani dosha puja and Shani Shanti puja to please Sani. They do this puja for reduced or minimised effects of Shani dosha. Some people observe fast on the day of Shani Triodasi. Thailabishekam is one of the most popular pujas to worship Sani and to pacify the effects of Sani.