The phrase "calling it a day" is commonly used to indicate that a particular activity or work has ended. However, there are several antonyms for this phrase, which signify the opposite, such as "continuing", "persisting", "persevering", "prolonging", and "carrying on". These words suggest a desire to continue with the task or activity, rather than ending it. For instance, someone who is determined to finish a project may choose to persist rather than calling it a day. Similarly, someone who is passionate about their work may choose to carry on with it, even when they are tired or pressed for time.