The fasting observed on Saturday (Shanivar Vrat) is mainly undertaken by those people who believe in astrology and that they are having a hard period in life due to the malefic influence of Lord Shani or Saturn. Another deity that is worshipped on the day is Lord Hanuman.
Saturday fasting or Shanivar Vrat begins before sunrise on Saturday and ends on the next day morning. A single meal is taken in the evening after prayers. Food prepared usually consists of sesame til or black gram or any other black colored food item. Salt is avoided on the day.
Black is the color of the day. The offerings made to Lord Shani include black sesame seeds (Til), urad dal, black clothes, Sesame oil etc. Black iron idol of Lord Shani is worshipped on the day usually at nearby temple which has a shrine for Shani or Navgraha. Some worship the Peepal Tree and tie thread around its bark.
People avoid long journey on the day. In some communities wives do not visit their paternal home on the day.
The Saturday fasting is believed to keep away all misfortunes and hurdles.
Lord Hanuman is worshipped on the day by many people to escape from the wrath of Lord Shani. Legend has it that Lord Hanuman had rescued Shani from Ravana. This happened during the burning of the Lanka episode in the epic Ramayana. Lord Shani had then promised that he would not trouble Lord Hanuman devotees.