The tradition of celebrating the Old New Year comes from the discrepancy between the Julian calendar (or otherwise the "old style" calendar) and the Gregorian calendar - the one that almost the whole world now lives by. The divergence of calendars in the 20th-21st centuries is 13 days.
The Old New Year is a rare historical phenomenon, an additional holiday that resulted from a change in the chronology. Due to this discrepancy in calendars, a number of countries celebrate two "New Years" - according to the old and new styles. Thus, on the night of January 13-14, everyone can afford to "complete" their favorite holiday. Indeed, for many believing Orthodox people, the Old New Year is of particular importance, since they can celebrate it wholeheartedly only after the end of the Nativity Fast.
Interestingly, the difference between the Julian and Gregorian calendars increases every century when the number of hundreds in the year from the birth of Christ is not a multiple of four, by one day. Therefore, from March 1, 2100, this difference will be 14 days.
Today, the popularity of the Old New Year is growing from year to year, and Russia is no exception. More and more people treat it as an independent holiday that prolongs the charm of the New Year or allows you to feel this charm for the first time ... After all, this holiday is calmer, it is not characterized by the fuss that is an inevitable companion of the New Year's celebration.