UK and Ireland's Position Relative to the International Date Line

West of the Line—One Day "Behind" the East

The **International Date Line (IDL)** roughly follows the 180° meridian. The **UK and Ireland lie between 0° and 10°W**—firmly in the Western Hemisphere, **west of the IDL**.

Practical Consequences

• When it's **noon Wednesday in London/Dublin**, it's **already Thursday in Tokyo/Sydney** (east of IDL).
• Conversely, **noon Thursday in Tokyo** = **still Wednesday in the UK/Ireland**.
• Flight example: London → Tokyo departure Wednesday → arrival Thursday (gain a day).

Why It Matters

The IDL standardizes global datekeeping. Without it, circumnavigation would create date confusion. The UK/Ireland's position means they "start the day later" than Asia/Oceania but "earlier" than the Americas.

Note: The IDL deviates for political boundaries (e.g., Kiribati, Samoa) but not near Europe.