Do you know 10간 and 12지? It was used for time and date in ancient Korea. 12지 are 12 kinds of animals. In other countries, it has other animals. For now, in Korea only numbers are used for time and date, but there are some words that remain. I attached a zodiac timetable. Each hour is separated into two parts. The first part is called 초, the second part is called 정. In Korean, midnight is 자정. It means middle of rat time. In ancient, 자정 means from midnight to 1 am. But now, 자정 only means midnight in Korean. Do you know noon in Korean? It's 정오, middle of horse time.