Which solar terms represent the beginning of summer?

Long summer is the seventh solar term in the twenty-four solar terms of the lunar calendar and the first solar term in summer, which indicates the official start of the summer season. When the sun reaches 45 degrees of the yellow meridian, it is the solar term of long summer.

In ancient times, China, as an agricultural society, attached great importance to the solar terms in the long summer. Every day in the long summer, the monarch and his subjects put on Yu Pei's red dress, horses and car flags of the same color, and held a welcoming ceremony in the southern suburbs of Beijing under the leadership of the emperor to express their prayers and expectations for a bumper harvest.