Bhai Dooja' is observed on the second day of the bright half of the lunar month, Kartika (October-November), the eighth month of the Indian calendar. As the same suggests this festival is dedicated to the welfare of brothers, particularly by sisters. Brothers visit their sisters who mark the holy 'Tilak' on their foreheads and feed them with choicest sweets. Brother's and sister's affection is a typical feature of the Hindu community. Of course all communities must be having these kinds of love and affection between the brothers and sisters but they don't manifest it through a full fledged festival, that too twice a year. Incidentally both the festivals fall on the second day of a lunar fortnight - while that in Kartika just after the moon-less day (Diwali) and in Chaitra just after the day when Holi is celebrated.
Although family ties are held paramount in the Hindu way of life, sister"brother relationship is unique in the sense that a sister is totally a guileless creature. One of the Sanskrit terms for sister is 'Duhita' which literally means one who ensures the welfare of two families. However, the Sookta claims that the real meaning of 'Duhita' is one who wishes welfare of the family (of brother-father) even while staying away: 'Door-hit-chintan' is the root that is believed to define the real meaning of this term. According to the Hindu belief when a daughter is married off in some other family, she had her interests shifted totally to that family. She doesn't have any share in her parents' property by the Mitakshara Law - the law that is adhered to by most of the Hindus. And even if she has any right it is very nominal.
Hence barring the occasional visits to her parents' place, she has no roles to play in the household she is born in. Of course it is customary for the brothers to give her gifts on the formal occasions but even if they don't she has no legal right upon it. So a sister is a creature that expects nothing from her brother but affection and in return she gives him unbound affection. This concept of relationship might appear somewhat out of place in a world wherein material interest is believed to be paramount. There are many stories and legend that have been woven around this relationship to emphasize the selfless love of a sister. One of them are narrated below.
The following one is a mythological legend which also emphasis's the brother-sister affection, attributing the bore to the death-god Yama and Yami or Yamuna, the sacred river. Taking bath in this river on this day is believed to be very auspicious and it is customary for the brothers and sisters to take bath jointly in this river.
Surya Narain (sun) had a beautiful wife. Her name was Sangya.
She gave birth to children. One was Yama and the other was Yamuna. Sangya was a delicate lady. She could not bear the heat of Surya Narain, the sun. She took her permanent abode in the North Pole.
During the course of time, Yama and Yamuna got separated from each other due to family problems. Yama became Yamraj and ruled over Yamalok, the abode of the God of death. Yamuna went to Golok Dham, the abode of Lord Krishna. Before Lord Krishna took incarnation, Yamuna came to earth. She constructed a beautiful house there and settled down permanently.
After some years, Yama remembered his sister. He sent a special messenger to her to take her to his domain. Yamuna did not agree. Yama decided to visit her himself.
Yamuna was pleased to see her brother at her doorstep. She hugged him and arranged best dishes for him. Yama was pleased with the hospitality. He asked her for some blessing.
Yamuna said, "Whosoever takes bath in my water shall not visit your domain i.e., the World of Death."
Yamraj said, "0, dear sister, your water flows for thousand of miles. Millions of people take bath in it. If I grant this boon to you, Yamalok will have a deserted look very soon. Do not ask for my destruction. You may ask for some other boon."
Yamuna said, "Today is Bhaiya Dooj. Let this day be a permanent day for union of brothers and sisters. The brother who visits his sister this day should not visit your 10k." Yama said, "I accept it. Those brothers who do not visit their sisters on this day and do not take bath in your holy water shall be caught in my snare of death. I shall ask my messengers to take such people to my domain."
The ritual on this day is only the sister applying the 'teeka' on her brother's forehead and give him sweet. The brother in return gives her some gifts or even money in cash. The thali of Puja generally contains the following items: Coconut, Batashas (hollow sweet balls made of sugar candy), other sweets, seven betel leaves, Roli (vermilion) and a little of rice grains.
Not withstanding the modern needs and compulsions altering the form the spirit is still intact. The puja itself is carried out in the Puja room, or on the same holy square (Chowk) that had been decorated for Diwali (for the festival falling just after Diwali)". The puja is performed with lighting the lamp. Then sister applies the 'Tilak', and gives to brothers sweets and then they all assemble to listen to the stories connected with this festivals. Two of which have already been given above.
The whole idea behind this brother-sister affection-highlighting festival is that those who have no share in your prosperity could also be your well-wisher.