At the instigation of U.S. Secretary of State William Seward, the United States Senate approved the purchase of Alaska from the Russian Empire for $7,200,000 on April 9, 1867, and the United States flag was raised on October 18 of that same year (now called Alaska Day). Coincident with the ownership change, the de facto International Date Line was moved westward, and Alaska changed from the Julian calendar to the Gregorian calendar. Therefore, for residents, Friday, October 6, 1867 was followed by Friday, October 18, 1867; two Fridays in a row because of the date line shift.[2]