London is also the capital of England, one of the constituent countries of the UK.
London is on Greenwich Mean Time (GMT) only during winter months.
The GMT time zone has the same hour offset (GMT+0) as the Western European Standard Time Zone.
Compare time as shown by the two clocks. GMT is time at the Shepherd Gate Clock, at the Royal Observatory in Greenwich, UK. GMT stays the same all year round, no DST (Daylight Saving Time) rules apply.
Until 2017, visitors to central London and Londoners alike were able to check time in London London and the whole of the UK just by looking up near the Parliament. A majestic tower, Elizabeth Tower, houses what is likely the most famous clock in the world, affectionately known as Big Ben.
Its chimes have always been as iconic as its face. On 21 August 2017, at midday, Big Ben chimes sounded once more before the start of major maintenance work. These chimes were heard again on Remembrance Day (11 November) and they ushered in the New Year 2018. Big Ben is expected to remain silent till 2021.
The British Parliament has a special section of its site devoted to Big Ben, including questions and answers.
Would like to view how many days have passed since the New Year and how many are left until 2021? Try the Date Calculator.
Greenwich was a royal park and palace on a hill to the south of the River Thames, east of London.
In 1675 the great race to create accurate maps for navigators had begun and Charles II offered the land to The Royal Society for Britain's first national observatory. Christopher Wren was commissioned to design the domed building and John Flamsteed was appointed the Astronomer Royal.
British mapmakers began to set Longitude from Greenwich. In 1884 the International Meridian Conference decided that the meridian passing through the main transit instrument at The Royal Observatory in Greenwich would become the Prime Meridian.
Every 15° longitude represents one hour's difference in time: (24 x 15 = 360, the degrees of a circle). You can work out the time at every location on earth if you know how many degrees it is east or west of Greenwich.
The GMT Carousel provides you at a glance with your local time, its GMT offset and main GMT offsets across the globe.
For a multi-functional tool, use the GMT Time Converter: choose a place and view the local time instantly and just one tab away you can customize your preferred clocks, see what is a mutually agreeable meeting time and even see the dark side of Planet Earth!