What is the fifth natural period of spring?

In the fifth paragraph of Spring Zhu Ziqing, the author describes the spring breeze through pleasant and beautiful feelings, highlighting the vitality of the spring breeze and highlighting the softness of the vernal equinox through smell, hearing and touch.

It shows the fresh and fragrant characteristics of spring breeze.

"Blowing the cold breeze" is good, like a mother's hand touching you. The wind brings some freshly turned earthy smell, mixed with the smell of grass, and the fragrance of various flowers, which are brewing in the slightly moist air. Birds nest in flowers and young leaves. They are very happy. Calling friends to show off their crisp voice and singing songs that echo the breeze and flowing water. Cows carry a shepherd boy's piccolo on their backs.