What Country Is a Day Behind?

The Cook Islands and Niue are independent countries that are a day behind many other parts of the world due to their location. This temporal difference is governed by the International Date Line (IDL), an imaginary line on Earth's surface that largely follows the 180° longitude line, defining the boundary between calendar dates.

When crossing the International Date Line from west to east, a traveler effectively "loses" a day, meaning they arrive in a region that is a day earlier. Conversely, crossing from east to west results in "gaining" a day. Countries and territories positioned to the east of the IDL are among the last places on Earth to experience a new calendar day.

Nations and Territories East of the International Date Line

Several regions are situated to the east of the International Date Line, placing them a day behind the western side of the line. These include both independent countries and overseas territories.

• American Samoa: An unincorporated territory of the United States.
• The Cook Islands: A self-governing island country in free association with New Zealand.
• Niue: A self-governing island nation in free association with New Zealand.
• French Polynesia: An overseas collectivity of France.

These locations, being east of the IDL, are typically one day behind countries like New Zealand or Samoa, which are west of the line. For instance, when it's Monday in New Zealand, it would still be Sunday in American Samoa.

To better illustrate these entities and their status, refer to the table below:

The precise course of the International Date Line has been adjusted over time to accommodate political and economic considerations, ensuring that entire nations or island groups generally remain on the same calendar date.

For more detailed information on global time zones and the International Date Line, you can explore resources like the International Date Line on Wikipedia.