Where did Chang 'an come from in February and March?

It is the ancient meaning of Chang 'an.

In Chang 'an in February and March, the spring breeze blew from thousands of families. Jade stands high, cars and BMW go hand in hand.

Spring, the first of the four seasons, refers to the period from beginning of spring to long summer, including solar terms such as beginning of spring, rain, fright, vernal equinox, Qingming and Grain Rain. Spring represents warmth and growth. In spring, the qi of yin and yang begins to change, and everything germinates with the rise of yang. As far as solar terms are concerned, spring in China begins in the beginning of spring (February 2-5) and ends in the long summer (May 5-7). In Europe and America, spring begins at the vernal equinox in China and ends at the summer solstice. In Ireland, February to April is designated as spring. At present, the division of four seasons in China often adopts the method of "climate average temperature" proposed by modern scholar Zhang Bao. Taking the five-day average temperature as the standard, the five-day average temperature after winter passes 10℃ and begins to enter spring. When the temperature is higher than 22℃, it means the end of spring and the beginning of summer.