Here's the thing about Christmas in America.
When we celebrate the holiday of Christmas on the 25th of December and then work through all the flack about how it was stolen from the pagans and how Jesus wasn't actually born on that day and then you appropriate the tree symbolism into your house and home. And then continue on by giving gifts and kissing under the mistletoe and carolling and participating in parties, etc. When after the presents are unwrapped and you sit down in front of the TV and play your new video game or watch a movie and enjoy some hot tea or egg nog. Do you see what I'm getting at? We're doing all of this in celebration of, not only God's bountiful, giving nature, but on behalf of His "only begotten Son" (John 3:16).
The beauty of modern-day Christmas tends to be overshadowed by an influx of activity and hedonism. You can understand how many people (to a certain degree, myself included) look forward to it all being over and jumping back into their year-round routine.
I say all of this to remind you of what is important, namely Jesus.
"For we brought nothing into this world and it is certain we can carry nothing out." (1 Timothy 6:7) The blessings and the bounty and the beauty of what God gives us both materially, physically and spiritually deserve a commensurate response in gratitude, praise and worship. Of course, I'm talking to myself here because, let's face it, I usually get pretty cool stuff for Christmas. But if the wonder of the presents fades (it will) and you wonder why you're struck with a feeling of emptiness in spite of the atmosphere (and also what to do about it), then may I simply suggest a passage from the Psalms (34:1): "I will bless the Lord at all times: His praise shall continually be in my mouth. My soul shall make her boast in the Lord: the humble shall thereof and be glad. O magnify the Lord with me, and let us exalt His name together. (and here's the kicker) I sought the Lord, and He heard me, and delivered me from all my fears."
So-o: Happy Birthday to Jesus!
I'd celebrate it on whatever day and as I don't have the power to unravel thousands of years of history and Christendom and tradition, December 25th is good enough for me.