Samoa became the first country to celebrate New Year's Eve on December 31, 2011, after moving west across the International Date Line.
Before the change, Samoa's clocks were 21 hours behind Sydney and nearly a full day behind New Zealand. At the end of December 29, 2011, Samoa skipped December 30 and moved directly to December 31. The change aligned Samoa's calendar more closely with its main trading partners in Australia and New Zealand.
The reform was a national time-zone decision, not a natural movement of the date line. Samoa had previously been on the eastern side of the line, despite lying relatively close to countries that conducted much of its business on the western side. The skipped date meant that the country experienced a 23-hour calendar day during the transition.
American Samoa, a separate U.S. territory, remained on the other side of the date line. The two Samoas therefore celebrated New Year's at different times, despite their geographic proximity.