A common opener in classical folk songs and yuefu (
乐府) poetry — the 《
十二月歌》 tradition runs through Tang, Song, and Ming verse. One well-known example is Lu You's (
陆游) Song-dynasty poem 《
岁首书事》『
一年十二月,
此月一年中』, marking the first month as the year's threshold. The line reads as a calendar-opening formula rather than a philosophical claim.