|Sweden's Double Leap Year|
In 1999 a rumour swept across the world: the year 2000 was a double leap year, with a February 29th and 30th. After prompting endless questions in discussion boards and other forums, this quirk of the calendar turned out to be a vastly successful hoax. But few people realized that there had already been a double leap year.
In 1700 Sweden decided to adopt the Gregorian calendar. To change from their current Julian date to the Gregorian one the Swedes needed to lose eleven days; however, instead of dropping them all in one year like the rest of Europe, Sweden used a different method. Their plan was to simply continue with their calendar as normal, omitting the leap days; by dropping every February 29th between 1700 and 1740 Sweden would slowly convert to the Gregorian date. Although this method would have left Sweden out of sync with the rest of Europe it prevented the economic and legal problems experienced by other nations.
Despite a good start - 1700 was not a leap year - the plan soon ran into problems, as 1704 and 1708 both contained leap days. At some point between 1708 and 1712 a decision was taken to abandon the plan and re-align Sweden with the Julian calendar. Consequently, in Sweden 1712 contained two leap days: February 29th was the normal one, while February 30th replaced the day omitted in 1700.
Sweden later changed to the Gregorian calendar in 1753, dropping the required days in one single block.
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