equation of time

American

noun

Astronomy.

apparent time minus mean solar time, ranging from minus 14 minutes in February to over 16 minutes in November.

equation of time British

noun

the difference between apparent solar time and mean solar time, being at a maximum in February (over 14 minutes) and November (over 16 minutes)

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of equation of time

First recorded in 1720–30

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

equation of time

But the boring dystopia meme reminds us the end could arrive quietly but corrosively, with a total erosion of work-life balance, crowdfunding for necessary healthcare, infantilisation by technology and the equation of time with capital.

From The Guardian ● Aug. 6, 2018

This difference between GMT and solar time is called "the equation of time" by astronomers.

From BBC ● Dec. 20, 2014

The equation of time and the sidereal time of mean noon complete the ephemeris proper.

From Side-Lights on Astronomy and Kindred Fields of Popular Science by Newcomb, Simon

To determine the longitude.—With an ordinary watch observe the time of the sun's transit over your local meridian, and correct the observed time for the equation of time by means of the curve in Fig. 30.

From A Text-Book of Astronomy by Comstock, George C.

The equation of time is to be applied as given in the Nautical Almanac when changing Mean Time into Apparent Time.

From Lectures in Navigation by Draper, Ernest Gallaudet

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023