Time-keeping from sundials to computer clocks
Global time, local clocks
At first it was the sun and time passed by day and by night, with shadows marking the intervals as long as the sun was up in the sky. The moon and the stars offered a measuring tool at night time.
There is a long way from using Nature's timepieces to the latest clocks and watches of ultra-precision. In between, Greenwich Mean Time(GMT) emerged as an essential point of reference.
Would you like to find out more about:
- The Earth, the Sun and GMT
- GMT offset clock
- GMT and time on a grid
- Where is GMT used nowadays?
- The GMT timestamp
- NIST clock
- The evolving definition of the second
- Leap seconds
- What do A.M and P.M. mean?
- An exception to Roman numerals
- Chiming 5 minutes after GMT
- A clock with two minute hands
- BBC pips and GMT
- SI unit of time
- Network Time Protocol
- Atomic Time Scale