Kwanzaa is a week-long celebration held in the United States and also celebrated in the Western African Diaspora in other nations of the Americas.
The celebration honors African heritage in African-American culture, and is observed from December 26 to January 1, culminating in a feast and gift-giving.
It was created by Maulana Karenga, and was first celebrated in 1966–67.
There you go. No threat to Christmas or any other holiday.