"In doing business with New Zealand and Australia, we're losing out on two working days a week.
"While it's Friday here it's Saturday in New Zealand, and when we're at church on Sunday they're already conducting business in Sydney and Brisbane."
Work has started on changing maps, charts and atlases to show Samoa on the western side of the International Dateline.
A new postage stamp has been created to mark the switch.
The change has drawn positive and negative reactions.
One objector is the Seventh-day Adventist Church, which observes the Sabbath on Saturday.
Church leaders in Samoa have declared they will continue to observe their holy day on what would have been Saturday - therefore observing the Sabbath on Sundays from now on.
But in the village of Samatau, church members say they will not be following the rule and will worshipping on the new Saturday.
The village of Falealupo - on the eastern tip of the big island of Savaii - has long been known as the last place on Earth to see the sun set each day.
This has made it a tourist attraction for decades, particularly during New Year celebrations.
Falealupo Beach Fales accommodation - which has a picture of a sunset and the line "where the sun sets" in its logo - will have to make some changes.
But owner Soifua Levi told the Herald yesterday that he accepted the time change.
"I believe that the Government is only trying to better our country ... I think we just have to go along with what they think is best.