mean solar day


Definition of mean solar day

: the interval between successive transits of a given meridian by the mean sun

Examples of mean solar day in a Sentence

Recent Examples on the Web In the 19th century, scientific institutions worked to define the second in astronomical terms, and in the 1940s an international agreement defined the second as 1⁄86,400 of a mean solar day. Jay Bennett, Popular Mechanics, "The Centuries-Long Quest to Measure One Second," 24 Mar. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mean solar day.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of mean solar day

1816, in the meaning defined above

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Cite this Entry

“Mean solar day.” The Dictionary, Merriam-Webster Inc., Accessed 12 December 2019.

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