Do atheists deserve to celebrate christmas and why?

Well firstly yes,,because Christianity stole the mid winter pagan festival held at that time,,they supplanted their new Christmas day on top of the old pagan festival to make it more appealing to the old fashioned pagans (us),and another point you may wish to mention,I presume all your friends have Christmas trees in the houses ,a pagan symbol imported by Prince Albert in the mid 1800s from his ancestry which was German,Germanic peoples used to take the fir tree into their houses in mid winter, it was something to do with life even in mid winter, Mistletoe was also a pagan ( actually Druid) sacred plant,it wasn`t until quite recently that the church allowed mistletoe to be hung in parish churches,,