2. The period of the earth's revolution on its axis. Ordinarily divided into twenty-four hours. It is measured by the interval between two successive transits of a celestial body over the same meridian, and takes a specific name from that of the body. Thus, if this is the sun, the day (the interval between two successive transits of the suns center over the same meridian) is called a solar day; if it is a star, a sidereal day; if it is the moon, a lunar day. See Civil day, sidereal day, below.
4. A specified time or period; time, considered with reference to the existence or prominence of a person or thing; age; time. A man who was great among the Hellenes of his day. (Jowett (Thucyd)) If my debtors do not keep their day, . . . I must with patience all the terms attend. (Dryden)
5. (Preceded by the) Some day in particular, as some day of contest, some anniversary, etc. The field of Agincourt, Fought on the day of Crispin Crispianus. (Shak) His name struck fear, his conduct won the day. (Roscommon)
day is much used in self-explaining compounds; as, daybreak, daylight, workday, etc. Anniversary day. See anniversary, astronomical day, a period equal to the mean solar day, but beginning at noon instead of at midnight, its twenty-four hours being numbered from 1 to 24; also, the sidereal day, as that most used by astronomers. Born days. See born. Canicular days. See dog day. Civil day, the mean solar day, used in the ordinary reckoning of time, and among most modern nations beginning at mean midnight; its hours are usually numbered in two series, each from 1 to 12. This is the period recognised by courts as constituting a day. The babylonians and Hindoos began their day at sunrise, the Athenians and jews at sunset, the ancient egyptians and romans at midnight. Day blindness.
The mean or average of all the apparent solar days of the year. One day, One of these days, at an uncertain time, usually of the future, rarely of the past; sooner or later. Well, niece, i hope to see you one day fitted with a husband. . Only from day to day, without certainty of continuance; temporarily. Sidereal day, the interval between two successive transits of the first point of aries over the same meridian. The sidereal day is 23 h. 56 m. 4.09 s. Of mean solar time. To win the day, to gain the victory, to be successful. Week day, any day of the week except Sunday; a working day. Working day. A day when work may be legally done, in distinction from Sundays and legal holidays. The number of hours, determined by law or custom, during which a workman, hired at a stated price per day, must work to be entitled to a day's pay.