The phrase "most day-and-night" indicates a continuous or uninterrupted state of activity or presence. However, there are several antonyms that describe the opposite of this state, such as occasional, intermittent, sporadic, infrequent or periodic. These antonyms indicate a break or halt in an activity or presence, which is the opposite of constant or always present. For instance, an occasional break from work is necessary for a healthy work-life balance or intermittent rainfall brings relief to the scorching heat of summer. Thus, antonyms for "most day-and-night" emphasize the importance of rest and balance in life.