Schedule of Services
For visitors, it might be strange to see some church events listed with two dates (for example, "Dec. 25/Jan. 7"). This is done because the Russian Orthodox Church uses the Julian calendar for religious purposes. It is slightly different from the Gregorian calendar, which most of the world uses for business, school, and other civil purposes. These two calendars are historically related, and they have the same arrangement of days, weeks, and months. However, the Julian calendar is presently thirteen days behind the Gregorian calendar. For example, some people think that Russians celebrate Christmas on January 7, and by the Gregorian measurement, that would be correct. But by the Church calendar, the Julian calendar, that same day is actually called December 25 (a thirteen-day difference).
Sometimes we list both dates, especially for important feasts. In those cases, the later of the two dates will be the one to pay attention to, if you are planning based on the world's "normal" (Gregorian) calendar. If only one date is mentioned, you may assume that it is according to that "normal" calendar.
There is much to be said about the history of the Christian calendar. Interested readers may wish to read this short article from one of our monthly bulletins.