Where is the Greenwich Meridian?
The famous brass strip seen at the Old Royal Observatory in Greenwich, London, marks the Airy meridian referred to in the 1884 treaty. However the meridian to which the UK Ordnance Survey is tied lies 5.79m to the west, while the GPS satellite meridian lies 96.5m to the east. The International Date Line: The International Date Line is an imaginary line of longitude located about 180 degrees east (or west) of the Greenwich meridian. This is the line across which the date changes by one day. To understand this, imagine it is 3pm GMT on January 3 at Greenwich. 15 degrees east of Greenwich the local time will be 4pm, one hour later. In Japan, 135 degrees east, it will be 9 hours later, and the local time will be midnight January 3/4, while in East Australia, 150 degrees east, it will be 1am on January 4th. In New Zealand, close to the International Date Line, the local time is 3am on January 4th. Now let us return to Greenwich and imagine travelling west towards America. For every 15 degre
