What caused the earliest autumnal equinox since 124 this year?

This year we have ushered in the earliest autumnal equinox in recent 124 years, and the autumnal equinox is one of the 24 solar terms. Geographically, the autumnal equinox means that the direct sunlight moves from the tropic of Capricorn to the equator, and the northern hemisphere ends the summer with long days and short nights. At the autumnal equinox, the world is divided equally between day and night, and the direct sunlight begins to move to the tropic of Capricorn. As the days get shorter and the nights get longer, our days will get shorter, the sunrise will be later and the sunset will be earlier. The reason why the autumnal equinox came early this year is also related to natural factors such as astronomy, geography and calendar.

In fact, the arrival time of the same solar term is more or less different every year, which is basically five or six hours later than the previous year. However, if it is postponed all the time, the same solar terms will be completely disrupted and moved to other seasons after many years, and it will no longer have the function of reminding solar terms. Therefore, every leap year, solar terms will come around 1 day in advance. This year is 2020, which is a leap year, so it is normal for the autumnal equinox to come early.

As we all know, February has 28 days and leap year has 29 days. Because there is an extra day in February, the autumnal equinox should be advanced by one day. However, this year's early is not the usual early, but the earliest autumnal equinox since 124, which is also related to the lunar calendar. This year is the year of boxer and leap year. The leap year in the double sense makes the autumnal equinox come earlier this year. As the crystallization of ancient wisdom, solar terms are very accurate. Even if they arrive ahead of time, they still effectively promote production activities.

So we can see that the early arrival of the autumnal equinox is related to the movement of the sun and the provisions of the calendar. This is the concentrated experience of ancient people after long-term observation and summary. It has guided people's endless life and struggle for thousands of years, allowing us to make correct judgments in agricultural production and avoid losses caused by weather seasons. Even if the autumnal equinox comes early, it is essentially in line with the calendar and has no negative impact on our life, work and rest.