We often hear that certain Christian commemoration days are pagan. This is not so; but certain Christian commemoration days were pagan, but these were very cleverly converted to Christian days by the early Christian pilgrims, as they converted the pagans. The pagans now celebrated Easter, but with their pagan eggs, etc. which they previously used to celebrate demons: an egg, in the end, is but an egg!
For example, easter with the eggs and rabbits (symbols from pagan worship) Christians converted to a Christian feast, after day cleverly persuaded/maneuvered the clan chiefs this way. Thus the early Christian converters cleverly devised their plans, allowing pagans to keep their feast dates and symbols, but adding the cross and replacing the Gods worshipped and doctrine taught to Christ and the Gospel.
In this new manner, the converted pagans then celebrated their feasts, but not in the name of wooden Gods but in the name of Christ. This was very clever and there is nothing wrong with these feasts, for no pagan Gods are worshipped. Go deep into the Amazon forest and try to convert a bushman to see how hard it must have been for those early Christians. This is why they devised their plans and tricks in such a manner that they did not face un-surmountable opposition from the pagans.
Christians do not celebrate pagan feast. Anyone telling you otherwise you have been warned for in the bible!
Do you need to celebrate or observe Christian dates? No, you do not, as they are not commandments from God. Nobody is obliged to observe Christianist celebrations, for these, are from men and not from God.
May I here also mention that Halloween is not anti-christ as it does not involve anything that he forbids. The creatures that go round in the evening are all made of latex and no spirits are conjured up or worshiped.