<P> The Russian Empire settled northwest North America from Siberia, from the west with its own Julian calendar (it did not adopt the Gregorian calendar until 1918). The United States purchased Russian America while based in the contiguous United States, from the east with its own Gregorian calendar (adopted in 1752 while several British colonies). The transfer ceremony occurred on the day that the commissioners appointed by the governments of Russia and the United States for that purpose arrived via the USS Ossipee at New Archangel (Sitka), the capital of Russian America . The United States recorded this date as Friday, 18 October 1867 (Gregorian), now known as Alaska Day, whereas the Russian governor, who had remained in New Archangel, would have recorded it as Saturday, 7 October 1867 (Julian). Senator Charles Sumner stated during his three - hour ratification speech (an encyclopedic discussion of Russian America) on Tuesday, 9 April 1867, that this day of the week and calendar discord should be changed . Because the transfer of ownership officially occurred at 3: 30 p.m. Sitka mean solar time (time zones were not yet in use), that was the date and time that Alaska changed from an Asian and Julian date to an American and Gregorian date . If the transfer had occurred at the preceding midnight then Friday, 6 October 1867 (Julian) would have been followed by Friday, 18 October 1867 (Gregorian), a duplicate day with a 12 - day difference appropriate both for changing from an Asian date to an American date (equivalent to moving the IDL from the east to the west of Alaska) and for changing from the Julian calendar to the Gregorian calendar during the 19th century . </P> <P> The Samoan Islands, now divided into Samoa and American Samoa, were on the west side of the IDL until 1892 . In that year, King Malietoa Laupepa was persuaded by American traders to adopt the American date (three hours behind California) to replace the former Asian date (four hours ahead of Japan). The change was made by repeating 4 July 1892, American Independence Day . </P> <P> In 2011, Samoa shifted back to the west side of the IDL by removing Friday, 30 December 2011 from its calendar . This changed the timezone from UTC − 11 to UTC + 13 . Samoa made the change because Australia and New Zealand have become its biggest trading partners, and also have large communities of expatriates . Being 21 hours behind made business difficult because having weekends on backward days meant only four days of the week were shared workdays . </P> <P> The IDL now passes between Samoa and American Samoa, which remains on the east (American) side of the line . </P>

Where is the international date line located on the world map