Antonyms for the phrase "being on duty" could include "off duty" or "not on duty." Other possible antonyms might include "not working," "at home," "relaxing," or "enjoying leisure time." These antonyms suggest a lack of responsibility, obligation, or expectation to be available for work or other duties. While being on duty can be necessary and important for certain professions, such as emergency services, law enforcement, or healthcare, it's also important to have periods of rest and relaxation to avoid burnout and maintain mental and physical health. By taking breaks from duty, individuals can recharge and be better prepared for the times when they do need to be on duty.