day one

noun

often capitalized D&O
: the first day or very beginning of something

Examples of day one in a Sentence

We've known this about the project since Day One. since day one of this project, we've always insisted that we would create the best product possible without any consideration of cost
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The All-American Rejects are headlining day one of the Kroger Wellness Festival, a free two-day event running Sept. 26-27 in downtown Cincinnati. Grace Tucker, The Enquirer, 7 Aug. 2025 Whether this is your first home or forever one, here’s your guide to settling in smoothly, safely and smartly from day one to day ninety. Allison Palmer august 4, Miami Herald, 4 Aug. 2025 Transparency in pricing was a hallmark from day one. Victoria Gomelsky, Robb Report, 4 Aug. 2025 The 20th Television Animation (formerly Fox Television Animation) series premieres on Monday, Aug. 4, on Hulu, while all 10 episodes will be available to binge-watch on day one. Season 14 of King of the Hill follows the Hill Family returning back home to Texas after years away in Saudi Arabia. Rudie Obias, HollywoodReporter, 1 Aug. 2025 See All Example Sentences for day one

Word History

First Known Use

1971, in the meaning defined above

Time Traveler
The first known use of day one was in 1971

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Cite this Entry

“Day one.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/day%20one. Accessed 19 Aug. 2025.

Last Updated: - Updated example sentences
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