Twenty-four solar terms make up a zodiac sign. Please explain why.

The corresponding relationship between the twenty-four solar terms and the twelve zodiac signs is as follows: there are positive yin (tiger), including the beginning of the spring rain, and there are February (rabbit), including the fright and vernal equinox; March (Dragon), including Qingming and Grain Rain; April 4th (snake), including Long Summer and Xiaoman; May afternoon (horse), including awn seed and summer solstice; At the end of June (sheep), including slight summer heat and great summer heat; July application (monkey), including beginning of autumn and early summer; August (chicken), including Millennium and autumnal equinox; Keep (dogs) in September, including cold dew and first frost; October Sea (pig), including beginning of winter and Xiaoxue; 1 1 month (rats), including heavy snow and winter solstice; Ugliness in December (cattle) includes slight cold and severe cold.