Beginning of spring should be today. Why is the 5th written on the calendar?

There are two "beginning of spring" dates because of the time difference.

The twenty-four solar terms reflect the movement of the sun in one year, which is divided according to the position of the sun on the ecliptic (that is, the orbit of the earth around the sun). Depending on the sun starting from the vernal equinox (longitude zero, at this moment the sun shines vertically on the equator), every advance of 15 degrees is a solar term; After running for a week, I returned to the vernal equinox. The vernal equinox is a tropical year, which is 360 degrees, so it is divided into 24 solar terms.

The dates of solar terms are relatively fixed in the solar calendar. The time in beginning of spring this year is 0: 50, that is, just after the demarcation point of the day. If calculated according to Beijing time, it should be February 4, that is, the tenth day of the lunar calendar. According to the time in Taiwan Province Province or other regions, it is still February 3rd. Because the calendars and desk calendars on the market are printed by different companies and enterprises, including Taiwan-funded enterprises, or according to the local time in Taiwan Province Province, there is a problem of holding the Spring Festival Evening for one day.