Universal Time UT, namely Greenwich Standard Solar Time, refers to the standard time in Greenwich, and is also a representation of the earth's rotation rate. Time measurement system based on earth rotation. The angle of the earth's rotation can be measured by the movement of the local meridian relative to the basic reference point on the earth. In order to measure the earth's rotation, people have chosen two basic reference points on the earth: vernal equinox (see vernal equinox) and Sun Point, and the determined time is called sidereal time and solar time respectively.
Beijing time is not Beijing local time (1 16.4 E), but the local time of East Eighth District (120 E), so the local time of East 120 E is about14.30 minutes earlier than Beijing local time. Beijing is named "Beijing time" because it is located in the East Eighth District of the international time zone, which is 8 hours different from Greenwich Mean Time (UTC) (that is, Beijing time = UTC +8 hours).
Extended data
Universal time is a time measurement system based on the earth's rotation. The angle of the earth's rotation can be measured by the movement of the local meridian relative to the basic reference point on the earth. In order to measure the earth's rotation, people choose two basic reference points on the celestial sphere: the vernal equinox and weekdays.
With the average sun as the basic reference point, the time determined by the average sun's apparent motion on Sunday is called the average solar time (MT).
Taking spring as the basic reference point, the time determined by the apparent motion of the vernal equinox on Sunday is called sidereal time (ST).
Before the introduction of standard time, every city in the civilized world set its official clock according to the position of the local sun (see solar time). This situation did not change until the introduction of railway travel in Britain, because the appearance of railways made it possible to travel long distances quickly enough, which required constant resetting of the clock, because the train would pass through several towns in its daily operation. In order to solve this problem, Greenwich Mean Time was established, all clocks in Britain were set to the same time, and they were synchronized by timers or telegrams.
References:
Baidu Encyclopedia-Beijing Time (China National Standard Time)? Baidu Encyclopedia-Universal Time