How does the great wisdom left by the older generation guide agricultural production?

The first threshold of agriculture is seasonality. I'm afraid it's still a question whether we can recover the seed money next year after missing the sowing season. Of course, a difference of one or two days between seasons is not a big problem. But I really missed a week or two or even a month ... eating people. Or starve to death. So every farming nation will have a pretty good calendar. This is a matter of life and death. Calendars are based on mathematics, geometry and astronomy. With the calendar, combined with the understanding of food crops, we know what to plant and what to harvest.