Friday, December 30, has been cut this year for the tiny South Pacific island nation as it ditched a time-zone alliance with the United States and moved its time zone 24 hours ahead to catch up with Asia, New Zealand and Australia.

On New Year's Eve, Samoa will have jumped to the west of the international dateline, which runs zig-zags through the Pacific Ocean and broadly follows the 180 degree line of longitude, in a move Prime Minister Tuilaepa Sailele Malielegaoi said would make it easier for Samoa to trade with key partners.

"No longer shall we have people ringing us up on Monday from New Zealand and Australia thinking it is Monday when we are closing our eyes and praying at churches. And vice versa on our Fridays when we ring up and already our contacts are holidaying on their Saturdays," he told Radio New Zealand on Friday.

"It will remove the enormous amount of confusion in our travel times for the Samoans and especially for the tourists who come to Samoa, who keep thinking of the New Zealand and Australian time zones."

Church bells will ring and carol services will herald the changeover time.

"I think the people are pretty calm about it, they are not expecting to have any major changes," said Samoa Observer newspaper editor Savea Sano Malifa.

To help win public support, the government declared employers must still pay workers for the missing Friday, although banks will not be allowed to charge interest for the lost day.

Countries are free to choose whether the dateline passes to the east or west, and Samoa's decision will mean all new maps will need to change.

The vast nation of China uses one national time zone while Australia is a mesh, particularly with summer daylight savings time that sees southern Adelaide city move from half an hour behind the eastern states to an hour in front of far northeastern Queensland.

But some tourism operators are worried Samoa will lose business by losing its position as the last place on earth to see the sunset each day, although it will now be one of the first places to see in each new day.

The nation's seventh Day Adventists are also divided over the change, and whether they should now observe the Sabbath on Saturday or Sunday.

The small former New Zealand dependency Tokelau, which has its administration in Samoa's capital Apia, is also changing datelines, while nearby American Samoa will continue to be on the other side of the dateline and will be a day behind.

Samoa, a country of about 180,000 people, used to be same time zone as New Zealand Australia but went back a day in 1892, celebrating July 4 twice and aligning itself with the United States.

The date change is not the first major change in Samoa in recent years. In 2009, the country switched to driving on the left hand side of the road from the right hand side, in line with New Zealand and Australia.