Jesus and God rejects all things Pagan (false Gods), the fact that throughout the entire bible there is no mention of birthdays would confirm that they are not a thing that should be celebrated. In fact they only started to celebrate them with the adoption of a heap of other pagan traditions.
The date that Christmas is celebrated (birth of Christ) is not his actual birthday, so why not do it on the day he was born, otherwise what is the point?
Easter, that is the Christian Easter, should again be a fixed point in time, not aligned to the stars and moon.
Every year, millions of professing Christians celebrate the supposed birthday of Jesus Christ. Yet they do not properly observe the day that Christ died, which God clearly identifies and records in great detail in His Word. He commands his followers to observe this memorial annually. Jesus warned about such misguided professing Christians, saying, “This people honors Me with their lips, but their heart is far from Me. Howbeit in vain do they worship Me, teaching for doctrines the commandments of men. For laying aside the commandment of God, you hold the tradition of men” (Mark 7:6-8). Each year, during the Christmas and Easter seasons, Jesus’ warning is proven right!