Bhai Dooj:
After the high voltage celebrations of the festival of lights and fire-crackers, sisters all over India get ready for 'Bhai Dooj' - when sisters ceremonize their love by putting an auspicious tilak or a vermilion mark on the forehead of their brothers and perform an aarti of him by showing him the light of the holy flame as a mark of love and protection from evil forces. Sisters are lavished with gifts, goodies and blessings from their brothers. 

Bhai Dooj or Bhau Beej as it is known, is the fifth day of the Diwali festival, which falls on a new moon night. The name 'Dooj' means the second day after the new moon, the day of the festival, and 'Bhai' means brother.  This day is special amongst brothers and sisters and is observed as a symbol of love and affection. The bond between them is strengthened on this day.
Traditionally the sister applies tilak (red vermilion) on her brother's forehead and performs on aarti (a Puja) of him, wishing him a long and successful life. In return, the brother blesses his sister and offers her sweets and gifts. 

This day is also known as Yama Dwiteeya as it is believed that on this day Yama Raj, the God of Death, visited Yami, his sister. She applied the tilak on his forehead and the spent happy moments together and exchanged special gifts as a token of love. Yama Raj then announced that anyone who received a tilak from his sister on this day would never be thrown. Hence till this day, the practice continues and brothers visit their sisters and the bond of love is strengthened.

Like all other Hindu festivals, Bhai Dooj too has got a lot to do with family ties and social attachments. It serves as a good time, especially for a married girl, to get together with her own family, and share the post-Diwali glee. 

Myths & Legends:
Bhai Dooj is also called 'Yama Dwiteeya' as it's believed that on this day, Yamaraj, the Lord of Death and the Custodian of Hell, visits his sister Yami, who puts the auspicious mark on his forehead and prays for his well being. So it's held that anyone who receives a tilak from his sister on this day would never be hurled into hell. 

According to one legend, on this day, Lord Krishna, after slaying the Narakasura demon, goes to his sister Subhadra who welcomes him the lamp, flowers and sweets, and puts the holy protective spot on her brother's forehead. 

Yet another story behind the origin of Bhai Dooj says that when Mahavir, the founder of Jainism, attained nirvana, his brother King Nandivardhan was distressed because he missed him and was comforted by his sister Sudarshana. Since then, women have been revered during Bhai Dooj.

Bhai Phota:
In Bengal this event is called 'Bhai Phota'. Two days after Kali puja, on dvitiya (second day), 'Bhai Phota' is celebrated. On this day, sisters keep a fast and invite their brothers to be felicitated. This event is ceremoniously performed by the loving sister who religiously fasts the whole morning until she applies a 'Phota' (tilak) of 'chandan' (sandal wood) paste, 'kaajol' and 'doi' (yogurt) on her brother's forehead, wishing him a long life and offering him sweets and gifts. The sisters make their brothers sit on an Asana (a small cotton mattress) and draws the 'Phota' on the forehead of the brother. If the sister is elder then she blesses her brother with rice grains and 'Durba' (blades of grass) when the brother touches her feet. It is customary on the part of the sister if she is elder, to draw the 'Phota' with the little finger of the left hand and with that of the right hand if she is younger from her brother. The brother also eagerly waits for his sister to apply the 'Phota' and in turn lavishes her with love and gifts, which marks the immense love and affection between the brother and sister. After this the brothers are served sweets and then the whole family engages into singing songs, play games and anything that is enjoyed by all. On this day relatives are invited to the house for lunch or dinner and thus a huge gathering of young children, teenagers and adults make the ambience more festive and cheerful. The sisters, dressed in their best, makes the arrangement for the 'Phota'.

Every brother eagerly awaits this occasion that reinforces the bond between brothers and sisters and their affectionate relationship. It's an opportunity for a good feast at the sister's place, coupled with an enthusiastic exchange of gifts, and merriment amid the resounding of conch shells in every Bengali household.

The Sanskrit version
Bhratus tabaa grajaataaham
Bhunksa bhaktamidam shuvam Preetaye yama raajasya
Yamunaah Visheshatah.

English Translation:
I’m your sister
Eat this sacred rice
For the pleasure of "Yam Raj" and "Yamuna".

Bengali version:
Bhaier kapale dilam phonta,
Jamer Duare porlo kanta,
Jamuna Dae Jomke phonta,
Ami di amar bhaike phonta,
Bhai jeno hoy lohar vata.

English Translation:
I put a "phota" on my brother’s fore-head
To make my brother immortal
"Yamuna" gives a "phota" to "Yam"
I give a "phota" to my brother
Brother may becomes tough as iron