dies (DEE uhs), di-, die-, -diem, diurn- +

(Latin: day)

Don't confuse this dies, "day" (DEE uhs) with the verb dies (DIGHZ) which refers to "dying" or "death".

antemeridian, antemeridiem (A.M.)
1. Of or belonging to the forenoon or "morning".
2. Before midday; applicable to the hours between midnight and the following noon.
Carpe diem, quam minimum credula postero.
Translation: Seize (take advantage of) the day and place no trust in tomorrow.

"Enjoy the present moment and don't depend on there being a tomorrow." -Horace

A continuing traditional theme in lyric poetry, dating back at least to Koheleth's "Eat, drink, and be merry" (based on Ecclesiastes 8:15). The phrase carpe diem exemplifies the spirit of hedonism and Epicureanism, i.e., the enjoyment of the moment and recognition of the transient nature of life.

So, carpe diem came from ancient times until the present with the advice often and variously expressed as: "Enjoy yourself while you have the chance"; "Eat, drink, and be merry, for tomorrow we die"; "Make hay while the sun shines"; "Enjoy yourself, it's later than you think."

William Safire had a different attitude regarding carpe diem when he wrote: "Seize the day has come to mean ‘strike while the iron is hot.' No longer is carpe diem the what-the-hell attitude of the dwellers in the present; it has become the battle cry of the gutsy opportunist with an eye on the future."

Many famous poems develop this "live it up now" theme; such as , the following by Robert Herrick (1591-1674):

Gather ye rosebuds while ye may,
Old Time is still a-flying,
And this same flower that smiles today
Tomorrow will be dying.
circadian
Designating physiological activity that occurs approximately every twenty-four hours, or the rhythm of such activity.
dial
An instrument serving to tell the hour of the day, by means of the sun's shadow upon a graduated surface; a sun-dial.
diary
1. A daily record of events or transactions, a journal; specifically, a daily record of matters affecting the writer personally, or which come under his personal observation.
2. A book prepared for keeping a daily record, or having spaces with printed dates for daily memoranda and jottings; also, applied to calendars containing daily memoranda on matters of importance to people generally, or to members of a particular profession, occupation, or pursuit.
dies non
A day on which no legal business is carried on. Literally, dies non (juridicus) is "a not juridical day".
dismal
1. The dies mali, evil, unlucky or unpropitious days, of the mediaeval calendar, called also dies Aegyptiaci, "Egipcian daies"; hence, by extension, Evil days (generally), days of disaster, gloom, or depression, the days of old age.
2. Of or belonging to the dies mali; unlucky, unpropitious.
3. Boding or bringing misfortune and disaster; unlucky, sinister, malign, fatal.
4. Of the nature of misfortune or disaster; disastrous, calamitous.
5. Of some character or an aspect that causes gloom and depression; depressingly dark, sombre, gloomy, dreary, or cheerless.
6. Of a character or aspect denoting gloom or depression; (subjectively) gloomy or miserable.
There is further information with illustrations about dismal on this page.
diurnal
1. Performed in or occupying one day; daily.
2. Of or belonging to each day; performed, happening, or recurring every day; daily. Of periodicals: "Published or issued every day."
3. A book for daily use, a day-book, diary; especially, a record of daily occurrences, a journal.
4. Of or belonging to the day as distinguished from the night; the opposite of nocturnal.

In zoology, specifically a reference to animals active only during the day.

Humans as diurnal creatures

If humans were really at home under the light of the moon and stars, they would go into the darkness happily and the midnight world would be visible just as it is to the vast numbers of nocturnal species on the Earth.

Instead, people are generally diurnal creatures, with eyes adapted to living in the sun's light. This is considered to be a basic evolutionary fact, even though most people don't think of themselves as diurnal beings any more than they think of themselves as primates, or mammals, or Earthlings.

Yet, it's the only way to explain the light pollution that humans have done to the night. Ill-designed lighting has washed out the darkness of night and radically altered the light levels, and light rhythms, to which many forms of life, including mankind, have adapted.

Wherever human light spills into the natural world, some aspect of the lives of other creatures is affected; including migration, reproduction, and feeding.

In most cities, the sky looks as though it has been emptied of stars, leaving behind a vacant haze that mirrors the fear people have of the dark and resembles the urban glow of dystopian science fiction; which includes, societies or states in which the conditions of human life are characterized by misery, poverty, oppression, violence, disease, and pollution.

—Excerpts from and modifications of "Our Vanishing Night" by Verlyn Klinkenborg;
National Geographic, November, 2008; page 106.
diurnally
In a diurnal way; every day; day by day; daily.
diurnation
The habit of some animals, of sleeping, being dormant, or remaining quiescent during the day, as contrasted with their activities at night.
diuturnal, diuturnity
1. Lasting a long time.
2. Being of long continuance.
journal
1. Performed, happening, or recurring every day; daily, diurnal.
2. A daily record of commercial transactions, entered as they occur, for the purpose of keeping accounts.
3. A daily newspaper or other publication; hence, by extension, any periodical publication containing news or dealing with matters of current interest in any particular sphere. Now often called specifically a "public journal".
4. Etymology: from about 1355, "a book of church services", from Anglo-French jurnal, "a day"; from Old French journal, originally "daily", from Late Latin diurnalis, "daily"; as in diurnal.

The sense of "a daily record of transactions" was first recorded in 1565; that of "a personal diary" is about 1610, from a sense found in French. "Journalism" in English is from 1833; as well as from French in about 1781.

lunardiurnal
A reference to the lunar day.
meridian
Mid-day, noon.
meridional
Pertaining to or characteristic of noonday.

Another related "day" unit is located at hemer-.