Synonyms for the phrase "sunup to sundown" include "daylight hours", "daytime", "working hours", "full day", "daylong", "sunshine hours", "daytime hours", "9 to 5", "day shift", and "waking hours". These synonyms all refer to the period of time between sunrise and sunset, when the sun is visible in the sky. This time is traditionally associated with productivity, work, and outdoor activities, and is often contrasted with the nighttime hours when the sun is not visible. Whether it's a day's work or leisure activities, these synonyms encapsulate the essence of a full day spent in the sunlight.