Excuse me, what does "this is cultivation" mean?

This is a sentence from the almanac. It means that if you work hard, you will become excellent and people will conquer nature.

Introduction to Gregorian calendar:

The almanac is a kind of almanac that can simultaneously display various calendars such as solar calendar, lunar calendar and dry calendar, and has a large number of rules and contents related to seeking good fortune and avoiding evil. In ancient times, the almanac was calculated and published by Qin, so it was also called the almanac. Its content guides the farming opportunities of Han working farmers, so it is also called the farmers' calendar. Han people are commonly known as general books. However, because the word "book" in Tongshu is homophonic with the word "lose", it is also called "Tong Sheng" because it is taboo.

Almanac, also known as almanac, is a code of conduct followed by ancient emperors. It includes not only astronomy, meteorology, seasons, but also some taboos that people should abide by in their daily lives. Because it can only be used by the emperor's family, it is called almanac. After the Revolution of 1911, the imperial system was overthrown and the almanac was rewritten as Almanac.

In modern times, the main contents of the Gregorian calendar include: Gregorian calendar, lunar calendar and trunk calendar, twenty-four solar terms and Sunday (week), taboos, disasters, directions, fleeting time, traditional calendar of China, three yuan and nine lucky days, mysterious nine planets and so on. Rich in content, different from each other because of its compilation and publication.