longitude.day

For centuries, sailors could determine latitude by the stars but longitude remained an unsolvable mystery. Ships were lost, fleets destroyed, fortunes squandered. In 1714, the British Parliament offered twenty thousand pounds to anyone who could solve the problem. John Harrison, a self-taught clockmaker, spent 31 years building marine chronometers of extraordinary precision.

The International Date Line does not follow the 180th meridian faithfully. It zigzags wildly across the Pacific, bending around island nations that refuse to be split between yesterday and tomorrow. Kiribati stretched its time zone in 1995 so the entire nation could share the same day. The Date Line is a negotiation between geography and politics.

Greenwich was not inevitable. France lobbied for Paris, the United States for Washington. At the 1884 International Meridian Conference, 25 nations voted, and Greenwich won — not by scientific merit but by empire. The prime meridian is not a fact of nature but an act of power, a brass strip in a courtyard floor in southeast London that organizes every clock on Earth.