if one is a day

== English == === Alternative forms === if a day, if one's a day === Etymology === (This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.) === Phrase === if one is a day If not older; at least. Antonym: at most He must be fifty if he's a day. ==== See also ==== not look a day over === Further reading === “if one is a day”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022. “if one is a day” in Longman Dictionary of Contemporary English, Longman. “if one is a day”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present. “if someone s a day” (US) / “if someone s a day” (UK) in Macmillan English Dictionary.