good day

American  

interjection

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

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good day British  

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

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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.

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Etymology

Origin of good day

Middle English word dating back to 1175–1225

Example Sentences

It’s never a good day to be fired, but Noem’s departure comes at a particularly unfortunate moment for her.

From Slate • Mar. 5, 2026

Eileen Shiffrin, Mikaela’s mother and original skiing Obi-Wan, says she knows it’s going to be a good day when her daughter is goofing off and chatty.

From The Wall Street Journal • Feb. 3, 2026

"It's a good day to have a Nordic temperament," Norway's Foreign Minister Espen Barth Eide diplomatically remarked to me when I asked about this moment.

From BBC • Jan. 20, 2026

Robo-taxis look like one reason Tesla stock is having a good day.

From Barron's • Jan. 5, 2026

Despite the State's early-morning maneuvers and the bad omen of the dog and Mrs. Williams, we had another good day in court.

From "Just Mercy" by Bryan Stevenson