How would you feel if you fell asleep on Thursday night and woke up on Saturday morning. No No; you didn't oversleep like crazy. Somebody moved the clocks. This is exactly what happened on 30th December if you were a Samoan - actually there was no 30th December. The world magically went from 29th to 31st. The reality behind the magic is quite prosaic. Samoa simply decided to come "this" side of the International Date line from "that".
The international date line is an arbitrary line that dictates where the easternmost and westernmost part of the world is. As you can see from the picture below it is not a straight line at all - quite arbitrary. If you fancy such things, you could have celebrated New Year's day in Tonga ; hopped across on a short plane ride to Samoa on the west of the line and celebrated New Year's day again. Alas, no longer.
Samoa does such things. Sometime ago they moved from driving on the right of the road to the left of the road - chronicled in this post. Now they have made everybody older by a day by just a wave of the wand. Such are the serious issues that the government of Samoa tackles.
The official explanation is that Samoa is on the side of the time zone which makes it one of the last countries to finish the day. That way they are on the same date as Hawaii and the rest of the US. But their biggest trading partners are now New Zealand and Australia - Kiwibloke, a regular commentator here has helpfully pointed out that there are more Samoans in Australia than there are in Samoa itself. But the time zones are such that Samoa is never on the same day as Australia - so when the Samoans are working (presumably) on a Friday, it is already the weekend in Australia (every sensible Aussie is on the beach ogling at Sheilas) and when the Samoans are "resting" on a Sunday, the Kiwis are already working on their Monday. This mismatch is apparently hurting the Samoans economically - hence this move !! Its amazing what you can justify on the grounds of economics these days.
We can hereby grant Samoa the title of the most entertaining and quixotic country in the world.