Why is Christmas celebrated on 25th of December?

Albertwhisker is absolutely right. The original pagan holiday celebrated the winter solstice and the hope for Spring. Catholics tried to take away from the "pagan" tradition by making it the celebration for the birth of Jesus. That's why when people get so upset about Santa on Christmas, I laugh to myself because the Catholics just made up the day and Santa doesn't interfere with the REAL birthday of Jesus.

Imagine winter on a manger jpertin. How are they going to survive if that is the case? Well, it's not that I am oppose to the tradition, but I think it was tampered by Some men. Since date weren't accurate before, we can't be sure.

all christianity people are celebrating the birth of jesus christ.every 25th of december.