The United States purchased Alaska from the Russian Empire on March 30, 1867, for 7.2 million U.S. dollars at approximately two cents per acre ($4.74/km²). The actual transfer of sovereignty took place on the 6th October 1867 (Julian calendar), which was equivalent to the 18th October in the Gregorian one. To complicate matters further, the time zone changed from 14 hours ahead of Greenwich to 10 hours behind, which meant that Alaska had two Fridays in succession, the only place to have ever done so. The area went through several administrative changes before becoming organized as a territory on May 11, 1912. It was admitted as the 49th state of the U.S. on January 3, 1959.