Christmas and Easter are condemned, as the root of them lies in paganism.
Galatians 4:8-11 Howbeit then, when ye knew not God, ye did service unto them which by nature are no gods. But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? Ye observe days, and months, and times, and years.
I am afraid of you, lest I have bestowed upon you labour in vain.
Christmas is not found anywhere in the Bible, and the only person to celebrate Easter is the wicked king Herod (Acts 12:4). Interestingly, the practice of decking a tree with ornaments is called the vain custom of heathen in Jeremiah 10:1-4.