solar day


Definition of solar day

: the interval between transits of the apparent or mean sun across the meridian at any place

Examples of solar day in a Sentence

Recent Examples on the Web The first division of the day’s 24 hours (known in Latin as partes minutae primae) gave them the length of the minute, which was one-1,440th of an average solar day. New York Times, 25 Apr. 2022 One solar day—a full day-night cycle—takes 176 Earth days. Jennifer Leman, Popular Mechanics, 9 Nov. 2019 It’s eleven-thirty at night according to my watch, but this far south the hour of the solar day is of no help in trying to understand the situation we’re in here, or our work rhythms. Barry Lopez, Harper's magazine, 10 Jan. 2019 In the 1980s and 1990s, the three scientists who received the award figured out how genetic time counters in cells aligned biological function to the 24-hour solar day. Jacqueline Detwiler, Popular Mechanics, 26 Dec. 2018 The length of a solar day, measured by the time between the sun’s passage of any particular point in the sky, is rarely 24 hours precisely. Scott Dance,, 13 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word '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 solar day

1751, in the meaning defined above

Learn More About solar day

Time Traveler for solar day

Time Traveler

The first known use of solar day was in 1751

See more words from the same year

Dictionary Entries Near solar day

solar cycle

solar day

solar diagonal

See More Nearby Entries 

Statistics for solar day

Last Updated

8 May 2022

Cite this Entry

“Solar day.” Dictionary, Merriam-Webster, Accessed 25 Jun. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More from Merriam-Webster on solar day Encyclopedia article about solar day


Test Your Vocabulary

Name That Food

  • a-light
  • Name these cookies!
True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!