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

Just keep in mind that the tired brain is not you on a good day.

From BBC • Jun. 13, 2026

If people happily complain about waking up the next day with sore feet, then it was a good day.

From Salon • Jun. 6, 2026

One of the drivers, Adrian, described it as a "good day to be a taxi driver", while another, Paul, said it was a "pain in the backside".

From BBC • Jun. 2, 2026

It’s a good day for markets, but it’s a great day for the Nasdaq Composite.

From Barron's • May 26, 2026

It would be a good day for the work detail.

From "The Great Santini" by Pat Conroy