Description: The International Date Line is a specific meridian which roughly follows the meridian of longitude 180°. The International Date Line passes north–south between Russia and Alaska, through the Pacific Ocean including parts of Micronesia and Polynesia, and to the east of Australia/New Zealand before reaching the South Pole on Antarctica. The International Date Line marks the boundary where calendar dates change by one. Therefore, regions to the west of the International Date line are one calendar day ahead of regions to the east.

Related Terms:

• Meridian
• Prime Meridian

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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