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Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
either one day
Grammar usage guide and real-world examplesUSAGE SUMMARY
'either one day' is a correct and usable phrase in written English.
It can be used to refer to a potential or hypothetical day in the future. For example, "I'm not sure when I'll finish the project, but I'll have it done either one day this week or the next."
✓ Grammatically correct
News & Media
Science
Academia
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified examples from authoritative sources
Exact Expressions
10 human-written examples
You'll notice in that first chart that there are a slew of gaps of either one day or five.
News & Media
Head to the main entrance jump off your tuk tuk and get a photo pass for either one day or three.
News & Media
Each individual added person-years starting at the 40th birthday and ending either one day before the 90th birthday, date of death or emigration or December 31 , 2008
Science
c the probe sets were significant with false discovery rate < 0.05 by either one – day or five – week estrogen treatment of ovariectomized rats.
Science
The nonprotein fermentation liquid had the lowest control among all E1R-j treatments whenever the time of application was (either one day before or after the fungal inoculation).
In the first experiment, when tumors reached an average size of 200 mm, the mice were treated with either one (day 0) or two intraperitonial injections (day 0, 2) of 1 mg/kg AP20187 dissolved 4% ethanol, 10% PEG-400 and 86% PBS-2%Tween.
Human-verified similar examples from authoritative sources
Similar Expressions
50 human-written examples
One other thing: "Harry Potter and the Cursed Child," which officially opens on April 22, has a running time of 5 hours and 15 minutes, and is staged in two parts (either seen on one day or on different nights).
News & Media
Last season, Adams' first in charge, Kent finished third in Division Two and failed to make the knockout stages of either one-day competition.
News & Media
The programme was six hours long, deliverable in either one full day or two half day equivalents, and facilitated by two educators.
Science
The NFL Show runs throughout the season on BBC One, either on Friday or Saturday nights, with NFL This Week rounding up all the action on Tuesdays on BBC Two.
News & Media
The feedback was binary: Each choice was associated with either one additional day of travel (winning option) or two additional days (the three losing options).
Science
Expert writing Tips
Best practice
Use "either one day" to suggest a choice or possibility concerning a single, unspecified day. This is particularly useful when presenting alternatives or options that are not time-sensitive.
Common error
Avoid using "either one day" in highly formal or professional documents where a more precise timeline is expected. Instead, opt for phrases like "at a later date" or "upon further notice" to maintain a more professional tone.
Source & Trust
85%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "either one day" functions as an adverbial phrase modifying a verb, indicating a potential time frame for an action or event. As confirmed by Ludwig AI, it's used to refer to a possible day in the future. Examples in Ludwig show usage in news, scientific, and academic writing.
Frequent in
News & Media
40%
Science
30%
Academia
15%
Less common in
Formal & Business
5%
Wiki
5%
Reference
5%
Ludwig's WRAP-UP
In summary, the phrase "either one day" is a grammatically correct expression used to indicate a possible event occurring on a single, unspecified day in the future. Ludwig AI confirms its usability in written English. It's most commonly found in news, science, and academic contexts, and while versatile, it's best reserved for situations where a precise timeline isn't required. Alternatives like "someday" or "at some point" can offer similar meanings, but "either one day" specifically suggests a choice among potential days. Be mindful of the context and avoid it in highly formal settings that require greater precision.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
someday
Single word alternative that conveys a similar sense of a future, unspecified time.
at some point
Implies an unspecified time in the future, shifting the focus from a specific day to a general time.
sometime in the future
More explicit about the timing being in the future, rather than necessarily on a specific day.
on a future date
Formally acknowledges a future occasion, less conversational than "either one day".
at a later time
General future reference, lacking the emphasis on a specific 'day'.
in due course
Suggests eventual occurrence but removes any sense of urgency or specific timing.
when the time is right
Adds a condition of suitability or readiness, differing from a simple future event.
in the fullness of time
Emphasizes a more distant or eventual future, contrasting with the potential nearness implied in "either one day".
eventually
A broad term for something that will happen later, doesn't specify the exact time.
sooner or later
Indicates that something will happen at some unspecified time, without reference to a specific day.
FAQs
How can I use "either one day" in a sentence?
You can use "either one day" to express a possibility or choice that might occur on a future, unspecified day. For example, "We could decide to visit the museum "either one day" this week or next week."
What are some alternatives to "either one day"?
Alternatives include "someday", "at some point", or "sometime in the future". The best choice depends on the specific nuance you wish to convey.
Is it correct to say "either one day"?
Yes, "either one day" is grammatically correct and understandable. Ludwig AI also confirms that it's usable in written English.
When should I use "either one day" versus "someday"?
Use "either one day" when you're specifically referring to a single day among possible days. Use "someday" when the specific timing is less important and you're simply referring to an unspecified future time.
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
85%
Authority and reliability
4.5/5
Expert rating
Real-world application tested