good day

American  

interjection

1. a conventional expression used at meeting or parting during the daytime.

---

good day British  

1. a conventional expression of greeting or farewell used during the day

---

good day Idioms  

1. Also,. Formal ways of saying “Hello” or “Goodbye.” For example, He began rather oddly by addressing the audience with “Good day,” or “Good afternoon, ladies,” said the sales clerk as we walked out. All these greetings represent an abbreviation of the now obsolete God give you a good day (afternoon, etc.), which dates from about 1200. Also see good night.

---

Etymology

Origin of good day

Middle English word dating back to 1175–1225

Example Sentences

See Examples For:

good day

So this date might be a good day for fans to mark in their diaries for a possible announcement.

From BBC ● Sep. 6, 2026

For those players in particular, each medically cleared to return, every day off crutches is a good day.

From Los Angeles Times ● Jul. 29, 2026

Tuesday wasn’t a good day for International Business Machines.

From The Wall Street Journal ● Jul. 15, 2026

“The student-loan system is confusing on a good day, and we’re moving into a period where there’s likely to be heightened confusion,” she said.

From MarketWatch ● Jul. 1, 2026

It might be a good day to be out of Moscow.

From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin