Ahaha!
"Passed down from Christianity", that's hilarious. You think religion came before people?
In Hinduism, Buddhism, Jainism and Sikhism, dāna is the practice of cultivating generosity. It can take the form of giving to an individual in distress or need. It can also take the form of philanthropic public projects that empower and help many.
Hinduism is older than Christianity, Christianity is renowned for co-opting aspects of other religions.
You only celebrate Christmas in Winter because it was a pre-existing festival.