What does one day mean?

A while ago, a reader pointed me to a comment on another writer’s OUPblog piece. The comment complained about a caption on a photo, an image of the painting “Adam and Eve in Paradise” by the seventeenth-century Flemish painter David Teniers the Younger. The original caption read “The world was also young one day,” and the comment read

The caption to Adam and Eve pic “the world was also young one day” should be “the world was also young once”. “One day” is only for indeterminate future time.

The reader who pointed this out to me wondered whether the claim that “One day” is only for indeterminate future time” was a legitimate correction or, as he put it “nonsense.” I responded that I was pretty sure that “one day” was not only for future tense. The blog editors didn’t get into the grammatical issue, but changed the caption to “Adam and Eve in Paradise. The age of innocence.”

The whole exchange got me curious about the expression “one day.” The original caption “The world was also young one day” does seem a bit odd, but certainly there are plenty examples of “one day” in the past sense, for example:

One day I was out walking, and passed by the calaboose; I saw a crowd about the gate, and heard a child’s voice…

Harriet Beecher Stowe, Uncle Tom’s Cabin

One day I was drawing a picture merely to fill in a blank space in the daily cartoon.

Rube Goldberg, The American Magazine, Jan 1922, 64

One day I was down on my knees polishing a man’s shoes on State Street when I happened to look up, and there was my teacher just passing.

Eddie Foy, “Clowning Through Life,” Colliers, Dec. 18, 1926, 7

In the examples, the one day signals something that that happened in the past. Try substituting once or one time and you’ll get a different, less specific narrative effect. One day is like Once upon a time, but without the fairy-tale feel.

Curious, I checked what dictionaries had to say. The Oxford English Dictionary is clear, telling us that one day means refers to “On a certain (but unspecified) day in the past.” It gives examples from Daniel Defoe and George Bernard Shaw, among others:

One Day walking with my Gun in my Hand by the Sea-side, I was very pensive upon the Subject of my present Condition.

Robinson Crusoe, 1881

I moralized and starved until one day I swore that I would be a full-fed free man at all costs.

Major Barbara, 1907

The OED notes as well that one day can refer to something occurring “On an unspecified day in the future” like the expression someday, as in this example from Tennessee Williams’s Twenty-seven Wagons Full of Cotton:

One day I will look in the mirror and I will see that my hair is beginning to turn grey.

The key feature, past or future, seems to be the idea of an unspecified day. The OED also contrasts one day with one of these days. The latter is described as also indicating an unspecified day in the future but as often “implying a more proximate or immediate future than the equivalent use of one day.” The OED gives an example from David Lodge’s 2009 Deaf Sentence:

It wouldn’t surprise me if we both turn up lightly disguised in a campus novel one of these days.

Try substituting one day or someday here and you’ll see contribution that one of these makes.

I didn’t find entries on one day in Garner’s Modern American Usage, Merriam Webster’s Guide to English Usage, The Chicago Manual of Style, in Websters Second or Third dictionaries or in the Random House Unabridged, all of which suggests that it is not a very contested bit of grammar.

Oddly though, the Cambridge Online Dictionary gives one day only as “at some time on the future,” citing the Cambridge Advanced Learner’s Dictionary & Thesaurus and the Cambridge Academic Content Dictionary.Collins Dictionary also gives one day “at some time in the future,” with no mention of the past.

Merriam Webster’s online dictionary treats one day as an idiom (perhaps to distinguish it from the literal sense of one day as “a single day”). Like the OED, Merriam gives both definitions: “at some time in the future” and “on a day in the past.”

The positioning of one day can also be a factor. When I looked through the full list of Merriam-Webster citations, I was struck by this quote from college football player Justin Dedich “My old soccer coach became the coach of pole vaulting and asked me to try out one day.” Here it is possible to associate the one day with the asking (an unspecified days in the past) or with the trying out (an unspecified day in the future, relative to the asking). The context makes it clear which is intended.

One day can refer to past or future events, and is part of a host of temporal settings phrases like once, one time, once upon a time, someday, and one of these days. Each has its own nuance.

_{Featured image by Marco Meyer via Unsplash.}