When Samoans go to bed on Dec. 29, it will be with the knowledge that when they wake up it will be Dec. 31.
No, they’re not planning on sleeping an entire day away. Instead, the country is going to skip Friday to better align itself with its major trading partners Australia and New Zealand. Located by the International Date Line, it’s currently near the spot where the day officially ends (Samoa currently bills itself as the last country to see the sun rise and set).
Australia & New Zealand aren’t that far away, but they’re on the other side of the Date Line, so they’re 21 and 23 hours ahead of Samoa. That makes it hard to sync up business dealings and other forms of interaction, so Samoa is going to move over to the other side of the Date Line. In the process, it will become one of the first countries to see the sun rise and set.
You can read more here. If you do, you can find out which countries currently claim that day begins there, and the circumstances around a previous Date Line shift Samoa made in 1892 where residents repeated a day to get into proper temporal alignment with the rest of the world.