What time is it?
A seemingly easy question.
But at any given moment, the time will be different in different places in the world.
While one person is waking up to breakfast at 7am, another will be heading off to bed at 10pm.
Local time all depends on what time zone you're in.
A time zone is simply a region on Earth, which is bound by longitudinal lines.
These lines, sometimes called meridians, run vertically from the North to the South Pole, each 15° apart.
Meridians break the world into 24 time zones.
A time difference of one hour per zone occurs with the rotation of the Earth.
If it is say 2pm at one meridian, 30° West will be two time zones, or two hours behind – so here it would be high noon.
Between zones 0 and 24, lies the international date line – where you cross from one day to the next.
But who decided what time it was, and where?
Greenwich Mean Time
Whatever time it is now, it is the result of an historic event in 1884.
Sir Sandford Fleming, Inventor
1827 – 1915
At the International Meridian Conference, Canadian Sir Sandford Fleming proposed that time begin at Greenwich, London – a major trade and shipping hub of the time.
Using Greenwich as the agreed universal meridian, the 24 time zones were established.
The system was known as Greenwich Mean Time.
By 1929, most countries had aligned their clocks accordingly.
Because your body clock is adapted to the time zone you live in, moving around the globe into other time zones can affect you.
If you travel from London to Los Angeles, for example, you'll be eight hours behind.
This means you'll be hungry when you should be sleeping, and nodding off when it's time to go out and explore.
The time on your watch was set over a century ago.
But wherever you go, it will be constantly changing.