The Amawasya, no moon day, that falls on a Saturday is called as Shani Amavasya. The day is dedicated to Lord Shani also known as Chhaya Putra, Sanaischarya and Shanishwara. People perform tarpan and Shradh for dead relatives. It is believed that worshipping ‘pitras’ (departed souls) on this day helps pitras to rest in peace and appease to bless the performers. Performing puja and daan on this day helps to mitigate the negative effect of pitra dosha and kaalsarp dosha. Observing vrat on the day helps to seek blessings of Lord Shani. In a year there are around 2-3 Shani Amavasya. In 2017, there are two Shani Amawasya, one was on June 24 and the other falls on November 17.
Prayers and mantras for Shani Dev are chanted throughout the day. Devotees observe fast on the day and break it after sunset by consuming rice mixed with sesame seeds or black urad dal. Those undergoing saadesati period or Shani Mahadasha are advised to observe vrat and perform puja on the day to get rid of the trouble and seek a peace of mind.
The idol of Lord Shani is bathed with water and black clothes are offered to the lord. Jaggery and Chana (Gram) are offered to the lord and bhog with black sesame seeds as an ingredient is offered. Sesame lamps are lit in front of the idol. To make sesame lamps, pour sesame oil in earthen lamps. Take a cloth and fill it with sesame seeds and tie it. Dip the cloth in the lamp and let it soak the oil. Once it properly soaks the oil light the closed end.
There is also a tradition of performing Chhaya Daan during Shani Amavasya. To perform the ritual, take mustard oil in a bowl or a plate and place it under your bed. Once you wake up in the morning look at your reflection in the oil and offer it any Shani temple. This is known as Chhaya Daan.
Amawasya tithi begins: November 17 at 3:29 pm
Amawasya tithi ends: November 18 at 5:11 pm