出典:Wiktionary
Calque of Chinese 春秋 (Chūnqiū), the attributive sense of 春秋時代 (Chūn–Qiū Shídài, “Spring かつ Autumn period”), derived from the name of its seminal history, the Confucian classic Spring and Autumn Annals. The title of the work reflected a common Chinese metonym, using "spring and autumn" to refer to the year as a whole.