First part is called Bhitauli and concluding part as Harela.
Bhaituli is celebrated in March – April. House women sow seeds in the soil and by the end of the festival that comes in July – August (also starting of the rainy season), they reap the harvest and this is called Harela.
This is just a unique combination of festival – testing of seeds, starting of rainy season. Perhaps not anywhere in the world.
A festival with such a strong agricultural ethics and protocol.
Brothers also give gifts to their sisters.
There is yet another mythological reason, as this festival commemorates the wedding of Lord Shiva and Parvati.