To correct an error, February 30, 1712 was added to the calendar in which country?

Sweden added the date to its 1712 calendar following an earlier calendar error; the Soviet Union observed February 30 in 1930 and 1931 in an attempt to cut seven-day weeks into five-day weeks and to introduce 30-day months for every working month.

In 1700, Sweden, which included Finland at the time, planned to convert from the Julian calendar to the Gregorian calendar.

Therefore 1700, which should have been a leap year in the Julian calendar, was not a leap year in Sweden. However, 1704 and 1708 became leap years by error. This left Sweden out of synchronization with both the Julian and the Gregorian calendars, so the country reverted back to the Julian calendar.

February 30, 1712, came into existence in Sweden when the Julian calendar was restored and 2 leap days were added that year. Sweden’s final conversion to the Gregorian calendar occurred in 1753, when an 11-day correction was applied so that February 17 was succeeded by March 1 that year. Not everyone was pleased with the calendar reform. Some people believed it stole 11 days of their lives.