“It seems that Christmas was usually observed on a Lord’s Day in Geneva rather than on 25 December.
“There were two reasons for this, quite aside from the “Puritan fanaticism” to which it is usually ascribed. The working people of Geneva were not too happy about stopping their work every few days for religious holidays. Holidays for the artisans of the late Middle Ages were a hardship, particularly when it became obvious that many of their apprentices found the holiday a good excuse for spending the day in the tavern. The middle class had good reason for objecting to frequent holidays. A Christmas observance which included Christmas, the feast of Saint Stephen, the feast of the Circumcision, the feast of Holy Innocents, Epiphany, and the feast of the Purification made for six holidays in a bit more than a month. This could also be a problem for a day laborer during the middle of winter, when there were extra expenses for fuel. The middle of the winter was no time to lose six day’s wages. But there was also a theological problem. It was well known in the sixteenth century that Christmas was originally a pagan feast day and that it was not until the fourth century that one began to celebrate the birth of Christ on the old birthday of the sun god. It was also well known that the Christian Church had been careful to celebrate the Christian Passover on a Sunday in order to make it clear that they were not simply celebrating the old Jewish feast. The Christians of the second century celebrated Easter on a Lord’s Day for the same reason the church of Geneva insisted on celebrating Christmas on the Lord’s Day.”
The Reading and Preaching of the Scriptures in the Worship of the Christian Church: The age of the Reformation, vol. 4, Hughes Oliphant Old, 2002, Grand Rapids; Eerdmans, p.122