Dashi, a Chinese word, is a unit of time in ancient China. One big hour equals one hour. "Da Shi" can also be called "Shi".
"Da Shi" can also be called "Shi". Because in the late Ming and early Qing dynasties, clocks and watches were introduced from Europe, which also brought new "time". In order to distinguish the two "shi", the original "shi" in China was called "Dashi" or still called "shi", while the one introduced from the West was renamed "hour".
