How Time Zones Were Created: Railways, Greenwich and 1884
Before the railways, every town kept its own local time, set by the sun. Standard time grew out of the need for one timetable.
Local time
A clock in Bristol ran about ten minutes behind one in London, because noon arrives later further west. This did not matter when a journey took days, but it did once trains made it possible to travel the length of the country in hours.
Railway time and the world
The Great Western Railway began using London time along its line in 1840, and other railways followed. In 1880 the UK made Greenwich Mean Time legal time. In 1884 the International Meridian Conference in Washington chose Greenwich as the prime meridian, and the idea of twenty-four standard time zones followed.
Frequently asked questions
When did the whole UK adopt GMT?
GMT became the legal time across Great Britain in 1880.
Clock change guides
- What Is Daylight Saving Time (DST)? A Plain-English GuideWhat daylight saving time is, how it works in the UK, Europe and the US, why it exists, its history, who uses it and the argument over scrapping it.
- Why Do the Clocks Go Back in October? The Real ReasonThe clocks go back in autumn to return the UK to GMT, so winter mornings are lighter. The history, the rule, what time it happens and what changes for you.
- When Do the Clocks Go Forward Again After Going Back?When the UK clocks go forward again after the autumn change, how long the UK stays on GMT, when evenings get lighter and how to remember to reset your clocks.