the period of time during which the earth makes one complete revolution on its axis relative to the sun
day (sense 6)
solar day in American English
Law
the period from sunrise to sunset
solar day in American English
noun
1. Astronomy
the time interval between two successive transits by the sun of the meridian directly opposite that of the observer; the 24-hour interval from one midnight to the following midnight
2. Law
the period of time from sunrise to sunset
Word origin
[1755–65]This word is first recorded in the period 1755–65. Other words that entered Englishat around the same time include: affiliate, avalanche, keynote, mitt, outfit
Examples of 'solar day' in a sentence
solar day
Originally the second was defined as 1/86400 of a mean solar day.
Globe and Mail (2003)
This is called a solar day and, strangely, it can vary throughout the year by about 15 minutes.
Times, Sunday Times (2016)
That seems to make good sense, except that the length of a solar day varies throughout the year by about plus orminus 15 minutes.
Times, Sunday Times (2018)
Throughout the year the length of a solar day changes slightly and is rarely exactly 24 hours.
Times, Sunday Times (2018)
This makes the solar day longer than 24 hours at the winter and summer solstices.
Times, Sunday Times (2016)
It also makes the solar day shorter than 24 hours at the spring and autumn equinoxes.
Times, Sunday Times (2016)
The solar days are now reaching their longest for the whole globe.