Happy new year to the 1,400 residents of Christmas Island in the Indian Ocean, who are the first in the world to celebrate the start of 2013, along with Kiribati and Samoa.
Preparations for the final countdown are gearing up across the world. Increasingly democratic Burma will have a public countdown for the first time.
Jakarta plans a huge street party befitting Indonesia's powering economy.
Happy new year the Chatham Islands, 420 miles southeast of New Zealand!
One day after dancing in the snow to celebrate the first anniversary of leader Kim Jong Un's ascension to supreme commander, North Koreans are now preparing to mark the arrival of the New Year, marked as 'Juche 102' on North Korean calendars - the number referring to 102 years since the birth of North Korean founder Kim Il Sung. 'Juche' means self-reliance, the North Korean ideology of independence promoted by Kim.
Sydney Lord Mayor Clover Moore said about 1.5 million spectators are expected to line the harbour to watch a 6.6 million Australian dollar fireworks display at 1pm GMT, while another two million Australians, among a population of 22 million, will watch it on television.
In the UK, tens of thousands of people are expected to descend on the streets of Scotland's capital tonight for the world-famous Hogmanay celebrations.
Simple Minds will headline the Concert in the Gardens, where they will be joined by The View and Bwani Junction against the backdrop of Edinburgh Castle. The street party is expected to see 80,000 party-goers welcome in 2013, with performances from Mercury Prize nominees The Maccabees and Reverend and the Makers.
There will be five live stages and countdown fireworks at 9pm, 10pm and 11pm, with the midnight display from the ramparts of the castle.
Celebrations got under way in Edinburgh last night with a torchlight procession. A record crowd estimated at 35,000 included 7,000 torch carriers.
In Scotland's capital, events will also take place on New Year's Day, including sled dog races at Holyrood Park and a triathlon which will see competitors swim 400 metres of the Royal Commonwealth Pool, cycle 11 miles around Arthur's Seat and then run 3.5 miles.
Happy New Year New Zealand!
In Hong Kong, which celebrates midnight at 4pm GMT, this year's 12.5 million Hong Kong dollar fireworks display is being billed by organisers as the biggest ever in the southern Chinese city. Police expect as many as 100,000 people to watch, local news reports said.
People have been camping out in Sydney all night, and the shores of the harbour were already packed when an eight-minute preliminary show for young children exploded three hours before the main event and as the clock struck midnight in Samoa and other South Pacific islands to the east, ushering in the New Year there.
Despite a somber mood in the Philippines due to devastation from a recent typhoon, a key problem for authorities on New Year's Eve remains how to prevent revellers from setting off huge illegal firecrackers - including some nicknamed 'Goodbye Philippines' and 'Bin Laden' - which maim and injure hundreds of Filipinos each year, including many children.
Hong Kong feng shui master Raymond Lo has predicted 2013 will be less turbulent than 2012 because the Chinese New Year in February will usher in the year of the snake, bringing an end to the year of the dragon, which was associated with water. Water is one of the five elements in feng shui theory, the Chinese practice of arranging objects and choosing dates to improve luck.
"Water is fear. So that's why we have had so much turbulence especially in the winter months," said Lo. "But the good news is that the coming year of the snake is the first time that fire has come back since 2007. Fire actually is the opposite to water, fire is happiness. So therefore the year of the snake is a much more optimistic year. So you can see signs of economic recovery now."