Kiribati moved across the International Date Line in 1995 so all its islands shared the same date.
Kiribati is spread across a vast area of the central Pacific, and its eastern Line Islands were previously nearly a day behind the country's western islands. In 1995, the country moved the date-line boundary around the Line Islands, aligning its calendar across its territory.
The change made Kiritimati, also called Christmas Island, one of the first inhabited places to enter a new calendar year. This is why Kiribati often appears in discussions of which locations celebrate New Year's first.
The International Date Line is not a perfectly straight legal line fixed by a single global authority. It bends around national borders and territories so communities can avoid being divided by different calendar dates. Kiribati's decision was therefore a political and practical adjustment to the line's route.