This is what the "Jehovah's Witnesses--Proclaimers of God's Kingdom," page 199 has to say on Christmas.
"This holiday was celebrated yearly even by members of the Watch Tower Society's headquarters staff at the Bethel Home in Brooklyn, New York. For many years they had been aware that December 25 was not the correct date, but they reasoned that the date had long been popularly associated with the birth of the Savior and that doing good for others was proper on that day. However, after further investigation of the subject, the members of the Society's headquarters staff, as well as the staffs at the Society's branch offices in England and in Switzerland, decided to stop sharing in Christmas festivities, so no Christmas celebration was held there after 1926.
"R.H. Barber, a member of the headquarters staff who made a thorough investigation of the origin of Christmas customs and the fruitage that these were yielding, presented the results in a radio broadcast. That information was also published in The Golden Age of December 12, 1928. It was a thorough expose of the God-dishonoring roots of Christmas. Since then, the pagan roots of Christmas customs have become general public knowledge, but few people make changes in their way of life as a result. On the other hand, Jehovah's Witnesses were willing to make needed changes in order to be more acceptable as servants of Jehovah."
We know that Charles Taze Russell had no problem with celebrating Christmas. And it seems that this divine revelation came from R.H. Barber, rather than Rutherford. Had he not made this startling discovery from other sources than the Bible, who knows, perhaps Jehovah's Witnesses would still be celebrating it today.