Examples of Rakhi.
Official name Raksha Bandhan
Also called Rakhi
Observed by Hindus, Jains, Sikhs, increasingly multicultural
Celebrations Sister-Brother get together, tie Rakhi on wrist, mark Tilak, brother promises to protect sister, sister feeds brother, brother gives gift, hugs
Date Purnima (full moon) of Shraavana
2014 date Sunday, August 10 
2015 date Sunday, August 29
2016 date Thursday, August 18
Related to Bhai Duj
Raksha Bandhan is a Hindu festival that celebrates the love and duty between brothers and sisters; the festival is also popularly used to celebrate any brother-sister like loving protective relationship between men and women who are relatives or biologically unrelated. It is called Rakhi Purnima, or simply Rakhi, in many parts of India. The festival is observed by Hindus, Jains, and many Sikhs. Raksha Bandhan is primarily observed in India, Mauritius and parts of Nepal. It is also celebrated by Hindus and Sikhs in parts of Pakistan, and by some people of Indian origin around the world.
Raksha Bandhan is an ancient festival, and has many myths and historic legends linked to it. For example, the Rajput queens practised the custom of sending rakhi threads to neighbouring rulers as token of brotherhood. On Raksha Bandhan, sisters tie a rakhi (sacred thread) on her brother's wrist. This symbolizes the sister's love and prayers for her brother's well-being, and the brother's lifelong vow to protect her. The festival falls on the full moon day (Shravan Poornima) of the Shravan month of the Hindu lunisolar calendar.