What season does the grass wither and the eagle suffer from eye disease, snow wither and horseshoe light describe?

The grass is dead, the eagle eye is sick and the snow is gone. The season described is the end of winter, and spring is still in the future.

If the grass is in bud, it is early spring anyway, but it is completely withered, only autumn and winter; There is "snow", which means that it is winter now, and "snow is gone", which means that winter is almost over, so it is the end of winter. According to the time of the month, it should be the middle and late days of the first lunar month. At this time, the grass on the plain has withered, the snow has disappeared, and the depression in late winter has a little spring, and there is little vegetation, so it is easy to find prey; The prey has little food, poor physical strength and is easy to hunt, which is a good time to hunt.