About the Russian calendar

The calendar used in Anastasia’s time, called the Julian calendar, was significantly different from the Gregorian calendar that was in use in most other parts of the world. The Julian calendar, named for Julius Caesar, had been in use for more than 1,500 years. The Julian year was 365 days and 6 hours – 11 minutes and 14 seconds longer than the time Earth actually takes to revolve around the sun. Over the years those minutes and seconds added up, so by AD 1580 the vernal (spring) equinox was actually occurring ten days later than the date shown on the calendar.

Taking the advice of astronomers, Pope Gregory XIII corrected the difference by dropping ten days and making some adjustments to the leap year with its additional day in February. In 1582, the Pope’s Gregorian calendar was adopted by most Roman Catholic countries in Europe. German states kept the old calendar until 1700, and Great Britain and the American colonies did not change until 1752. Russia and Turkey were the last to accept the new calendar, in 1918.

During Anastasia’s time, the difference between the old Julian calendar and the new Gregorian calendar had increased to thirteen days. Her parents and many other educated Russians sometimes used both systems, perhaps dating a letter written to a relative in England “23 October/5 November,” meaning that the letter was being written according to the “Old Style” Russian calendar on 23 October, but that on the Englishman’s calendar the date was 5 November.

The calendar of Christian feast and fast days was also affected. Christmas was celebrated on 25 December according to the Russian calendar, but that date was thirteen days later than Christmas in Germany, France, and the United States, where it was already 7 January of the following year. Easter is more complicated, because the date changes every year according to ancient formulas. But the Russian Orthodox Church and the Greek Orthodox Church use a formula that is different from the formula used by Western Christian churches. As a result, the Russian Orthodox date of Easter and other holy days related to it can vary as much as a few weeks from the date observed in the rest of the world.

Anastasia’s diary uses both Old Style and New Style dates, as her mother did in hers