When will Yanzi return to the North?

In spring, about January, most migration takes place at dusk or night. During the trip, we often choose lakes and other large waters to rest and look for food such as fish, shrimp and aquatic plants. Each migration takes about 1-2 months, and there are many hardships on the way. But they go north in spring and south in autumn and never break their word. No matter where you breed and spend the winter, you always go north and south on time. In ancient China, there were many poems praising them, such as "On the first day of August, geese opened and flew south with frost." Lu You's "Rain Ji Chicken Live Early, the wind is high and the array is oblique"; Wei's "Wan Li people go south, three spring geese fly north" (singing geese in the south), "Meng Chun is red in the north and Qiu Meng is red in the north", "Lv Chunqiu" and so on.