Thursday is dedicated to Lord Vishnu and his incarnations. Devotees offer puja using milk, ghee etc. Consumption of food is limited to one time in a day and contains milk products. Srimad Bhagavad Purana is read on this day of the week.

According to Hinduism, each day of the week is dedicated to a particular god. Thursday is Brihaspatiwar or Vrihaspativar, is dedicated to Lord Vishnu and Lord Brihaspati, the Guru of Devas. Thursday is also known as Guruvar, signifying the fact that it is dedicated to the Guru of Devas. Yellow is believed to be the color of the day. Some devotees observe a strict fast on the day, some limit the consumption of food to one time. Meanwhile in some areas, people make it a point to visit Hanuman Temple on the day.

According to popular beliefs, Lord Vishnu once appeared in front of a devout Hindu disguised as a mendicant to test the devotee on a Thursday. The devotee was believed to be Lord Vrihaspati. At first, the devotee neglects his duties towards the holy man and denies him alms and is lethargic but later when he realizes his mistake, he observes a ritual fast on Thursdays and appeases the gods. There are numerous stories associated with the reason for observing Upvaas, or fast, on Brihaspativar. Many of the stories are part of local folklore and stories vary from region to region.

Those devotees fasting on the day wears a yellow colored dress and offers yellow colored fruits and flowers to Vishnu and Brihaspati. Food is only consumed once and includes Chana Dal and ghee. Basically, yellow colored food is eaten on the day. In some regions, banana or plantain is worshiped and watered.