time tellers have been developed through time until now.the first device invented to measure the passage of time was the sundial.it measured the sun's shadow.then,the water clock was developed over the sundial since it didn't depend on the sun. the hourglass was created to make the passage of time with sand when the art of glass making was perfected.perfected.people created several way of keeping track of the passage of time.finally,we have seen and used many inventions of the digital clock or watch as today