The word **日夜** (rìyè) is a **binome** or compound word formed by combining two independent, monosyllabic morphemes: **日** (rì), meaning "day," and **夜** (yè), meaning "night." It follows a common coordinative structure in Chinese morphology where two related but opposite or complementary characters are joined to create a new, single concept that encompasses the meaning of both. In this case, the union of "day" and "night" forms the compound meaning "day and night," which figuratively expresses the idea of continuity, around-the-clock, or all the time.