Antonyms for the phrase "all one's born day" would include "brief," "fleeting," "momentary," "transient," and "ephemeral." These words suggest a temporary state or condition, as opposed to the enduring quality implied by "all one's born day." Other antonyms might include phrases like "short-lived," "limited," "intermittent," or "occasional," all of which contrast with the idea of a long and continuous lifetime. Antonyms for "all one's born day" invoke a sense of impermanence and change, highlighting the fleeting nature of human existence. They remind us to cherish every moment we have and to make the most of the time we are granted.