Before Time Zones: Solar Noon
Every town set its clocks to solar noon. Then came the railroads.
The Railroad Problem
In 1847, the Railway Clearing House recommended all British railways use Greenwich Mean Time. By 1855, 98% of British public clocks were set to GMT.
The International Meridian Conference (1884)
Representatives from 25 nations chose Greenwich as the Prime Meridian, establishing 24 time zones each 15 degrees wide.
Atomic Time
In 1972, UTC was established using atomic clocks, maintained by over 400 clocks in 50+ countries.
