Kiribati moved the International Date Line in 1995 so its inhabited islands would share one calendar date.
Kiribati is an island country spread across a vast area of the central Pacific Ocean. Before the change, its eastern and western island groups fell on different sides of the date line, creating a practical problem for government, travel and communication. The country shifted its time-zone arrangement so the date line would pass east of its inhabited islands.
The change took effect at the start of 1995. Kiribati then became one of the first countries to enter each new calendar year, although exact “first” claims depend on whether one means the first territory, inhabited place or national capital.
The date line is not a perfectly straight natural boundary. It is an international convention that bends around national borders and practical interests. Kiribati's decision did not move the entire global date line; it changed the country's time-zone relationship to it.