岁月 (suì yuè) is a poetic noun for 'years' or 'time', carrying emotional weight — it evokes the passage of time with nostalgia, reflection, or a sense of loss. Unlike 时光 (shí guāng), which often describes a beautiful or memorable period, 岁月 focuses on the cumulative, lived experience of time passing. It is more literary than 时代 (era) or 年纪 (age).