The idea that Christianity is not a religion comes as a surprise to many, since Christianity shares many external features with the religions of the world. One of these features is the use of a sacred calendar. Does our use of a Christian calendar mean that Christianity is a religion after all?
At first glance, our present use of a calendar seems somewhat problematic. The earliest Christians seem to have had no calendar apart from the weekly Sunday. As Jews they would meet with their fellow-Jews on the Sabbath and the other Jewish holy days, and on Sunday (called by them “the first day of the week”) they would gather with their fellow-Christians for the weekly Eucharist. Thus Sunday, the day when Christ the Lord rose from the dead and first appeared to them, became “the Lord’s Day” par excellence, the day of Christian assembly. But that seems to have been the totality of the apostolic Christian calendar. The other Jewish feasts they kept (such as Pentecost; compare Acts 20:16, 1 Corinthians 16:8) they kept as Jews and with other Jews. A distinctly Christian calendar as such did not yet exist.
More than this, Paul has harsh words for his converts who insisted on keeping a calendar. Thus though he regards the keeping or non-keeping of holy days a matter of complete indifference (Romans 14:5), he chides the Galatians for their new practice of observing days, months, seasons and years, wondering fitfully if perhaps he had laboured in vain over them (Galatians 4:10-11). He insists that the Colossians must not let anyone act as their judge regarding festivals, new moons or Sabbath days (Colossians 2:15) and insist that these be kept. Here we have to free ourselves from our secular experience of calendar “holidays” and understanding the significance of Jewish or pagan “holy days”, for a holy day was not a holiday. A holiday, as experienced in our contemporary society, is a day chosen more or less arbitrarily. In Canada, for example, we keep the last Monday preceding May 25 as the holiday “Victoria Day” (after Queen Victoria), but the date itself is not fixed—this year the date was May 22, whereas last year 2016 it was May 23. And governments can invent new holidays if they choose, to give workers a break from work in the form of federal or provincial “Stat” holidays. In other words, there is nothing inherently special about the day itself; the date of the holiday is only significant after it was arbitrarily chosen to bear certain (usually fairly minimal) significance.
It was otherwise with holy days in Judaism or in the pagan world. There the day was holy in itself, and could not be arbitrarily moved. The weekly Sabbath was holy because it was the seventh day, and a Jew could not move the Sabbath occasionally to work on Saturday and keep Monday instead as the Sabbath because it was more convenient. That is why Paul objected to his converts keeping calendar like they did—they were acknowledging thereby that the days were holy in themselves for Christians, when in fact they were not. Paul famously said that “neither circumcision counts for anything, nor uncircumcision, but a new creation” (Galatians 6:15). He had no problem with circumcision so long as one did not ascribe ultimate or saving significance to it, and thus he had Timothy circumcised for reasons of practical evangelism (Acts 16:3). It was only when someone ascribed such religious significance to circumcision (as the Galatians did) that Paul violently objected to it (Galatians 5:2). It is the same, I suggest, with the use of a calendar—one could paraphrase Paul and say “neither a calendar counts for anything, nor non-use of a calendar, but a new creation”.
This brings into focus the difference between our present use of a calendar and the religious use of calendar in Judaism or paganism. That is, unlike Judaism, we Christians do not say that any day is holy in itself. Our holy days are holy by virtue of their participation in the Eucharist on those days, and the days are chosen with a certain amount of arbitrariness. For example, we keep Annunciation as a holy day on March 25, but in our earlier history we commemorated the Marian event on other dates, such as in the weeks prior to Christmas. The addition of holy days to the Christian calendar such as feast of the Transfiguration did not occur because we discovered anything particularly sacred about August 6, but because we decided that was the day we wanted to celebrate the Transfiguration. Confirmation of this may be seen in the (admittedly regrettable) use of two calendars, “Old” and “New”: what matters is not the holy day itself, but what one does on that day. One may prefer the Old Calendar to the New (or vice-versa), but the preference is based on other considerations than the perceived holiness of the days themselves. Those wanting to celebrate the Transfiguration on August 19 do not say that the day itself is holier than August 6, but that the calendar system as a whole is to be preferred for historical reasons.
Christians therefore use a calendar not because we think that one day is holier in itself than another day, but because we want to celebrate certain events together and therefore need to agree about when we can do it. If I choose to celebrate our Lord’s Transfiguration on August 6 and you choose to celebrate it on September 6 we cannot celebrate the feast together. The use of a calendar therefore expresses the Church’s corporate nature and enables us to worship as a body. What matters is our corporate celebration of the feasts, not the date chosen for the celebration. The day of August 6 (or August 19) is indeed holy—not in itself, but because that is the day on which the Church serves the feast of the Transfiguration. And because our corporate nature matters and rejection of this unity involves a sin against love (i.e. schism), one is not free to reject the Church’s calendar or set up one’s own. The Church has chosen August 6/19 as the date for assembling for the feast of the Transfiguration, and those who consider themselves her children must keep the feast. Setting up a rival calendar is like setting up a rival altar—it involves a kind of temporal schism, and must be avoided.
Thus the Church has developed a calendar and continues to use it to express her corporate nature and celebrate the saving significance of certain feasts. But that does not mean we ascribe holiness to the days themselves. Ours is not a religious calendar, but a Eucharistic one.