February has in the Julian and Gregorian calendars only 28, in leap years 29 days. Due to a calendar conversion, there were in Sweden in 1712, but a 30th of February. In addition, there are several unreacted calendar designs, where has the February 30 or more days.
February 30 in Sweden
At the beginning of 1700 decided to Sweden to change from the Julian to the Gregorian calendar. The original idea was, beginning with the year 1700, the last time in 1740 to give up a total of eleven leap years and so gradually compensate for the difference between the Julian and the Gregorian day calendar. That would indeed have the switch within Sweden simplified, but relations with all other States made considerably more complicated, since Sweden then no other state had for 40 years the same calendar and on top of that the calendrical distance to the rest of Europe would have changed every four years. So February 29 was skipped in 1700. Sweden was now the Julian calendar and the Gregorian one day ahead ten days afterward.
During the Great Northern War, however, retained the leap day February 29, 1704 and 1708, so that the difference from one day to the Julian calendar and ten days remained to Gregorian. In January 1711, King Charles XII. Decided to Julian Calendar back again. The day the Swedes the chronology of this calendar was now ahead, had to be balanced by an extra day: This was February 30, 1712, a second leap, he was on a Friday and corresponded to the March 11, 1712 in the Gregorian calendar. The scheme was also true for the time dependent Sweden Finland, but not in the Swedish provinces in Germany, who had introduced with the other Protestant areas of Germany already in 1700 the Gregorian calendar. 1753 Sweden changed then finally to the Gregorian calendar.
February 30 in the Soviet Union
NA are occasional representations that it. In the Soviet Union as a result of the 1929 calendar was introduced, where each month had 30 days, had been in the years 1930 and 1931 a February 30
In Germany, every month is set at 30 days and the calendar year of 360 days with the " commercial " interest calculation for reasons of simplicity. Usually this method is used in credit transactions between merchants and economic education. Moreover, where a credit period, for example, from January 28 to March 3, then the interest days calculated as follows: January ( 30-28 ) February (30 ) March (3) = 35 interest days.
Some banks give reason to invoices for reasons of simplicity in each case the 30th of a month rather than the month - Ultimos. Thus, for example, as the value date of an invoice closing entry on the bank statement and the 30.02. , which can be specified result in a possible electronic processing problems.
February 30 in the Art
The Baroque poet Andreas Gryphius leaves at the end of his comedy Horribilicribrifax Teutsch ( 1663 ) date a marriage contract on February 30, 1648. This is a joke of the poet who wants implying that under the contract no consequences arise.