Morning-8 am to 12 am.

Noon-24-hour 12:00 or 12-hour noon 12: 00 is the middle of the day. When the sun is above the meridian. ?

Evening-18: 00-20: 00. Near the evening. Sunset disappears and the sky is not dark. It is yellow first and then dark, so it is also called "dusk". Refers to the time around sunset, that is, the transition time from daylight to evening.

Time explanation:

1, 12-hour system. It was used in the Western Zhou Dynasty. In the Han dynasty, it was named midnight, crow, pingdan, sunrise, food time, corner, Japan-China, sundial, sunset, dusk and people's decision. It is also represented by twelve earthly branches, with midnight from 23: 00 to 1: 00 as the child, 1: 00 to 3: 00 as the ugly time, and 3: 00 to 5: 00 as the yinshi time, which are recursive in turn.

2. 24-hour system. After the Song Dynasty, each of the twelve hours was divided into two parts, namely, the beginning of the child, the beginning of the child, the beginning of the ugly, and the ugly ... in turn, it was exactly twenty-four hours, which was consistent with the current twenty-four hours a day.