The time when the Sun is above the horizon and it lights the sky.
- day and night; I work at night and sleep during the day.
A period of time equal or almost equal to a full day-night cycle, being 24 hours long.
- Holonyms: week < megasecond < fortnight < month < year < gigasecond < century < kiloannum, kiloyear, millennium < terasecond < mega-annum, megayear < petasecond < giga-annum, gigayear < exasecond < zettasecond < yottasecond < ronnasecond < quettasecond
- Meronyms: quectosecond < rontosecond < yoctosecond < zeptosecond < attosecond < femtosecond < picosecond < nanosecond < microsecond < millisecond < centisecond < decisecond < second < decasecond < minute < hectosecond < kilosecond < hour
- I've been here for two days and a bit.
(informal or meteorology) A 24-hour period beginning at 6am or sunrise.
- Your 8am forecast: The high for the day will be 30 and the low, before dawn, will be 10.
A period of time between two set times which mark the beginning and the end of day in a calendar, such as from midnight to the following midnight or (Judaism) from nightfall to the following nightfall.
- The day begins at midnight.
- Monday is the first day of the week in many countries of the world.
(astronomy) The rotational period of a planet.
- A day on Mars is slightly over 24 hours.
The part of a day period which one spends at one’s job, school, etc.
- I worked two days last week.
An observance lasting for a day, such as an annual holiday.
- Christmas Day
- Remembrance Day
A specified time or period; time, considered with reference to the existence or prominence of a person or thing; age; time; era.
- every dog has its day; in that day; back in the day; in those days
A period of contention of a day or less.
- The day belonged to the Allies.