Many scholars have presented investigative data that prove "Christ was not born on December" but on a summer month, yet majority of the people still prefer to celebrate it on December.
http://www.ucg.org/doctrinal-beliefs/biblical-evidence-shows-jesus-christ-wasnt-born-dec-25/
http://www.ucg.org/bible-faq/when-was-jesus-christ-born-was-jesus-born-december-25-christmas-day
http://www.christiananswers.net/christmas/mythsaboutchristmas.html
http://www.livescience.com/42976-when-was-jesus-born.html
https://bible.org/article/birth-jesus-christ