Raksha Bandhan is celebrated every year on 'Shravan Purnima' (Full Moon Day of the Hindu month of Shravan), which generally falls in the month of August.
After the ritual of tying Rakhi is over, the brothers would give their sisters some gift or money and promise them to help them when ever they need and protect them throughout their lifetime. In fact, offering gifts to sisters is a tradition of Raksha Bandhan. Year by year, the enthusiasm amongst the brothers and their sisters, to celebrate the festival, is increasing. It is clearly visible from the wide variety of Rakhi, Raksha Bandhan gifts and sweets flocking the shelves of the stores, during the holiday. The festival bears social significance, because it symbolizes the importance of relationship between siblings.
R : Relationship
A : Affection
K : Knitting together
H : Him (Brother) & Her (Sister)
I : Interminably
Put them all together, they spell " RAKHI".