Skip to Content

Anyday or Any Day: Which Is Correct?

Some of the most challenging words to work with in the English language include idioms, phrases, and compound words. A key example is “any day,” which we might consider an idiom, a phrase, or a compound word. Which, then, is correct: “anyday” or “any day”?

“Anyday,” is not correct in English. The correct form is “any day,” which is an informal phrase containing the adjective “any” and the noun “day.” We also often use “any day” in the idiom “any day now.”

This article will explain why “any day” and “anyday” aren’t interchangeable and why only the former spelling is correct. I will also explain why it is a phrase and not a compound word. Finally, I will provide a list of words and phrases you can use instead of “any day” if you find it too difficult to remember the correct form.

What Does “Any Day” Mean?

According to Lexico, an online dictionary powered by Oxford, “any day” is an informal phrase that means “at any time or under any circumstances” (source). In other words, “any day” simply means “whenever.”

This definition makes sense given that the first part of the word is “any,” which is a determiner that denotes an unspecified quantity (source). 

You might compare this to the pronoun “anyone,” meaning an unspecified person or people in general, or the adverb or noun “anywhere,” meaning an unspecified location or places in general.

This raises the issue of whether “any day” is an idiom, phrase, or compound word. While grammatical structures are similar, they differ in important ways.

“Any Day” Is a Phrase

A phrase is a group of words that act collectively and perform a single grammatical function (source). For example, read the following sentence:

  • You can find the silverware in the kitchen.

The words “in the kitchen” comprise a type of phrase we call a prepositional phrase. Although they are three separate words with spaces between them, they serve a single purpose: to explain where you can find the silverware. 

Omitting “the kitchen” would not explain what the silverware is in, and omitting “in” would not explain the silverware’s relationship to the kitchen. 

“Any day” can function as a phrase for this same reason. Examine the following sentence:

  • You can bring me the lamp any day.

If we remove either of the words in this phrase, the sentence becomes unclear. We would not know what time the speaker meant. 

“Any Day Now” Is an Idiom

Idioms and phrases are similar in terms of both definition and usage. However, an idiom is actually a specific kind of phrase whose meaning we cannot determine from the typical definitions of its component pieces (source).

We also generally view idioms as informal. A good example is the idiom “out of my hands.”

When someone says, “It’s out of my hands,” they are not referencing a physical item that they have thrown or that is otherwise literally removed from their hands. Rather, they mean that something is out of their control or not their responsibility. 

On its own, “any day” does not constitute an idiom because it means what any native or non-native English speaker would expect it to mean — whenever. 

However, when we use it in the more common phrase “any day now,” it certainly becomes an idiom. Suggesting that the time can be both whenever and now is nonsensical and does not address the phrase’s actual meaning of “soon.”

Is “Any Day” a Compound Word?

Image by Snapwire via Pexels

Finally, compound words are collections of two or more words that act as a single word. English compound words take one of three forms (source):

Closed: we write the components of the compound word together as a single word — e.g., markup, baseball.

Hyphenated: we separate the components of the compound word using a hyphen — e.g., father-in-law, eighty-one.

Open: we leave a space between the components of the compound word — e.g., hot dog, grocery store. 

Differentiating a compound word from a word modified by an adjective can be quite challenging. When do we consider a word a compound, and when is it merely a phrase composed of at least two words?

Open Compound or Phrase?

Functionally, “any day” does not act as a single word. Instead, “any” is an adjective describing an indefinite or unspecified noun, “day.” It does not form a compound noun like “weekday,” a compound adjective like “everyday,” or a compound adverb like “anytime” (source).

Compound words can be very confusing for English language learners since the rules for forming compound words appear to be quite arbitrary. For instance, it is common for people to confuse the closed compound adjective “everyday” with the open adverb “every day,” which also contains an adjective and a noun. 

The adjective “everyday” usually goes before a noun to describe it as mundane or ordinary. In contrast, the adverb “every day” stands as two words to describe an action someone or something performs each day.

Curiously, “anytime” as an adverb is one word, and there is some overlap in meaning with “any day” since they can both mean “whenever.” However, there are times when “any time” is only a phrase, and we must separate the words.

One such circumstance is when we use “any time” with a preposition like “at.” Another instance is when we refer to time, like when we ask if someone has any time to do something.

As of yet, no dictionary recognizes “any day” as a compound. So instead, it functions as a phrase.

  • Any day of the week, you’ll find him sitting on his front porch.
  • She told me I could visit any day.
  • I can start my vacation on any day.    

Still, it is possible that “any day” could become a compound word, though it seems unlikely. Compounds like “everyday” and “anytime” seem to satisfy any role that a compound like “anyday” would fill.

How Compound Words Develop

Closed compound words enter the dictionary over a period of time after they have gained wide acceptance by English speakers as a single word. They often start as an open compound and then morph into a hyphenated compound before becoming a closed compound.

The original open compound is usually a noun with a modifying adjective. For example, if we look at the compound noun “mailman,” we can easily see how “mail” is a modifying adjective that describes the type of “man” in question — i.e., a man who delivers or works with mail. 

We also form new modifiers such as adjectives and adverbs in a similar manner. The adverb “anyhow,” for instance, originally had a space between the words, and people wrote it as “any how” when it first appeared in the 1700s (source).

One of the main benefits of closed compounds is that they make it easier for us to describe something without confusing our readers. In the case of compound nouns, it makes it easier to add other adjectives before the compound — for example, the fast mailman or the moody mailman.

If there was a space between “mail” and “man,” your reader might have trouble determining if “fast” referred to the mail or the man.

How Can I Identify Compound Words?

Compound words are difficult to master because there is no way to know if you should write a word in open, hyphenated, or closed form other than consulting a dictionary. In other words, you must memorize the spelling of each compound word in the English language.

For more help with common but tricky compound words, examine the following lists:


  • Dining room
  • Granola bar
  • High school
  • Hot dog
  • Ice cream
  • Ice cube
  • Key lime
  • News bee
  • Report card
  • Yard sale


  • Close-up
  • Father-in-law
  • Full-size
  • In-depth
  • See-saw
  • Self-service
  • Two-dimensional
  • U-turn
  • Well-off
  • X-ray


  • Afternoon
  • Background
  • Bathtub
  • Bedroom
  • Bookshelf
  • Cannot
  • Dashboard
  • Sidewalk
  • Teacup
  • Worthwhile

You can also check out our article “Goodnight or Good Night: Is It Two Words or One?

How Do You Use “Any Day” in a Sentence?

“Any day” frequently appears on its own as another way of saying “whenever.” To better understand this meaning, look at the following questions and apply “any day” as the answer:

  • Q: When can I come visit my grandmother? 
  • A: Any day.

We can also rewrite this as a statement, “I can visit my grandmother any day,” meaning that I can come visit my grandmother whenever. The implication in this sentence is that my grandmother can have me as a guest at any point in time. 

  • Q: When can she go to the store? 
  • A: Any day.       

She can go to the store any day. This sentence implies that the store is open every day of the week, so I can go there any day (or whenever) I want.

  • Q: When are you available for the meeting? 
  • A: Any day.   

You are available any day. The implication in this sentence is that you can attend the meeting at any point. You do not have any other engagements or appointments that would interfere with the meeting.

Note that each of these sentences includes the verb “can.” This is because “any day” typically describes the ability to do something, not a specific action. 

For example, I could rephrase the first question as, “When will I be able to visit my grandmother?” or “When will my grandmother be available for me to visit her?” Both of these reworded sentences emphasize that I am asking about which day works best for my grandmother’s schedule. 

The answer — any day — states that there is no specific day on which I couldn’t visit. In other words, all days are available.

Idiom: Any Day Now

Image by Vie Studio via Pexels

This is not the most common way English speakers use the word “any day,” however. Usually, we use “any day” in the phrase “any day now. The Merriam-Webster Dictionary defines this idiomatic phrase to mean “within the next few days, in the near future, or soon” (source). 

This phrase can appear at the beginning, middle, or end of a sentence. For example, look at the following examples:

  • Any day now, they’re going to finish tallying the votes. 
  • The baby is due any day now, so you should probably contact your midwife. 
  • My college acceptance letter should be arriving any day now.

Although the placement of the phrase differs, it carries the same meaning for all three sentences. Regardless of the situation, the phrase indicates something someone expects to happen in the near future.

Similar Expressions 

Similar phrases include “any minute now” and “any second now.” English speakers may use these three phrases interchangeably, but with the general understanding that “any day now” describes a lengthier timeframe than “any minute now” or “any second now.”

Another common phrase that utilizes the word “any day” is “any day of the week.” We’ve used this phrase in a few example sentences throughout this article, so, using context clues, you should be able to guess that it means “an unspecified day or all possible days of the week.” 

You may also see the related phrase “any day of the month,” which has the same meaning but with a timespan emphasis of months rather than weeks. 

“Any Day” Synonyms 

When we use it in phrases like “any day now,” the word “any day” means “soon.” This means that you can also use the word “soon” to replace those phrases in a sentence. You may find this method especially useful if you’re struggling to remember whether or not “any day” contains a space.

Other words you can use to replace these phrases include the following (source):

  • Before long
  • By and by 
  • Directly
  • In a jiffy 
  • In a minute
  • In no time 
  • In the near future
  • Quickly
  • Shortly

This article was written for 

When we use it by itself or in phrases like “any day of the week” or “any day now,” “any day” means the same thing as “whenever.” Other words you can use to replace “any day” in a sentence include the following:

  • At any moment
  • At any point
  • At any time
  • At [your] convenience
  • At [your] leisure
  • On any occasion
  • Whensoever
  • When [you are] available 

Final Thoughts

Any day now, we’re going to learn that “anyday” isn’t a word. Then again, it could very easily become one in the future if English speakers decide to adopt that spelling of the compound word formally. Until then, though, use “any day” when describing vague or open-ended dates and points in time.