"he and Denisov were leaving to join their regiment after Epiphany"

Epiphany in the Orthodox Church falls later than that of the Western Churches (6th January) due to the different calendars that have been used by the two churches. In the Russian Orthodox Church, Epiphany (also called the Theophany) on 19th January.

Epiphany marks the day when the Three Wise Men visited the baby Jesus in Bethlehem. As the wise men, or kings, carried gifts, in some Christian cultures presents are exchanged at Epiphany rather than on Christmas Day - for example, in Catholic Spain.

In Russia, some Orthodox Christians celebrate Epiphany by going for a swim in the freezing waters of their nearest lake or river. A hole, sometimes in the shape of a cross, is cut in the ice, and believers take a quick plunge to cleanse themselves spiritually in preparation for the year ahead.