A handheld watch worn on the forearm or in a pocket has a long and interesting history. The first instruments measuring time used a change in the position of the sun, casting a shadow on a flat shield. Several thousand years ago water and sand clocks were used, the so-called hourglass. In the eighth century a mechanical clock was made in China. In 1504, the first spring-powered pocket watch was created. Wristwatches were initially treated as a part of women's fashion and only during the First World War they were more commonly used among men in the army. In the 1960s the watches began to be equipped with a quartz movement, which were then replaced by electronic watches.
