Chinese medicine and astrology recognize 24 seasonal nodes that mark subtle changes in climate. Four of them correlate with the equinoxes and solstices that are used in the West to mark the beginning of the seasons. In the East, these dates are considered to be half-way points of the season. Thus the Chinese mark the beginnings of seasons six weeks before the official start in the West.
It is common practice in Chinese medicine to administer acupuncture treatments during the time of change from one season to the next, as the Qi of the body is changeable (our bodies respond and adjust to seasonal and other external changes) and subject to disturbance from similarly changing external climactic changes. Treatment at these nodal points serves as prevention from illness for the coming season.
Similarly and in addition, herbal formulas are used to support the body and help it to adjust to changing factors such as wind, heat and cold. For more on this topic, see The Concept of Wind in Chinese Medicine.
It is best to receive acupuncture and herbal treatment within one week before or after the seasonal change. To learn more about the seasons and elements, see the following articles: