February is the month on our calendar that has 29 days except during a leap year when there are 28. There was a time in history that there was a February 30th! It happened only once and it was in Sweden and Finland in 1712. At that time there were two different calendars in use, ‘the Julian calendar' and ‘the Gregorian calendar'.  Sweden and Finland decided to rejoin the Julian calendar whose date was February 29th, but the two countries were using the Gregorian calendar and the date was March 11. Sweden and Finland were set to change calendars on March 1, 1712, so they had to wait a day and added February 30.