| The following are some landmarks in the history of telling the time. |
| 1500 - 1300 BC | Sundials are used in Egypt: as the Earth rotates, the gnomon - the upright part of the sundial - casts a shadow which moves to indicate the time. |
| c 400 BC | Water clocks are used in Greece: as water drains from a container, each level it reaches represents a period of time. |
| c 890 | In England people use candles marked with time intervals |
| 12th century | The hourglass, familiar to us as an eggtimer, is used by monks to show times of prayer. |
| 1325 | The first clock with a dial is installed in Norwich Cathedral, England. |
| 1335 | The first clock to strike the hours is made in Milan, Italy. |
| 1350 | The oldest known surviving alarm clock is made in Wurzburg, Germany. |
| 1364 | Clocks are first used in people's homes. |
| 1386 | Salisbury Cathedral's clock is installed. This is the world's oldest clock in working order. |
| 1462 | The earliest description of a watch is written in Italy. |
| 1641 | The idea of the pendulum clock is proposed by Vincenzio Galilei, son of the famous astronomer Galileo. |
| 1657 | The first pendulum clocks are made in Holland. |
| c 1665 | The first watches with minute and second hands are made. |
| 1759 | John Harrison's marine chronometer is made. Accurate timekeeping at sea is important for calculating position, but previously the rolling of a ship had made it impossible. |
| 1880 | Greenwich Mean Time becomes the standard from which time around the world is set. |
| 1880 | The first practical wristwatches are made for the German navy. |
| 1928 | The first quartz crystal clock is made. |
| 1949 | The first atomic clock is built. |
| 1957 | The first battery watches are marketed in the USA. |
| 1969 | Quartz wristwatches are first sold in Japan. |
| 1970 | Digital watches and displays become widely used and can be made and sold cheaply. |
| 2006 | 40 radio clocks around the world transmit signals that enable people to set their clocks and watches accurately. |