How do foreigners know when it is a full moon?

This is the difference between the so-called lunar calendar and the solar calendar:

1. The lunar calendar, that is, the lunar calendar used by China, is based on the law that the moon revolves around the earth, so the moon is the roundest on August 15th of the lunar calendar. Because China was a big agricultural country in ancient times, the lunar calendar was the most suitable calendar for agricultural production. However, the lunar calendar is inaccurate and different when calculating the date of a year, so there will be a leap month every four years to adjust the difference in the number of days in a year, so that the next full moon will still be on the fifteenth day of the eighth lunar month. There are also several solar terms, such as vernal equinox, spring solstice, summer solstice and so on. (I can't remember), it will also be this time of year.

2. Gregorian calendar, also called Gregorian calendar, is a calendar determined according to the law of the earth's rotation around the sun. It is more accurate to calculate the earth's rotation and the time of rotation, so it is now universal.

In addition, don't ask why foreigners also know when the moon is full. You should know that there are moons and calendars abroad, whether lunar or solar, which are finally worked out by scientists after long-term research in astronomy and geography. Just as you go to eat when you are hungry, foreigners should eat when they are hungry. We can see what we can think and do, and foreigners can see and do it.

But we should also be proud of our ancestors. After all, this lunar calendar is unique in the world and is still the most suitable for agriculture.