Any Day vs Anyday: Which One Is Correct?

English has many small spelling and usage rules that can be surprisingly confusing. One common example is the difference between “any day” and “anyday.” The two forms look almost identical, but the space between the words matters. In standard English, “any day” is the preferred and correct form when you are talking about an unspecified day, a possible day, or a flexible choice of days.

Understanding this difference is useful for students, professionals, bloggers, and anyone who wants to write clearly. If you are working on your English Grammar, learning when to separate words can help you avoid simple mistakes that can make otherwise good writing look careless.

Any Day vs Anyday: The Quick Answer

The simple answer is:

Any day = standard and recommended
Anyday = nonstandard and generally avoided

For example:

• Correct: You can visit me any day this week.
• Incorrect: You can visit me anyday this week.

The expression “any day” contains two separate words. “Any” works as a determiner, while “day” is the noun it describes. Together, they refer to an unspecified day or any one of several possible days.

Although “anyday” may appear in casual messages, social media posts, or informal online writing, it is generally treated as a nonstandard spelling. Standard writing should use “any day” as two words.

What Does “Any Day” Mean?

“Any day” can have several closely related meanings depending on the sentence. Most commonly, it refers to an unspecified day or a day chosen from a number of possibilities.

Consider this example:

I can meet you any day next week.

Here, the speaker is saying that there is no particular day that must be selected. Monday, Tuesday, Wednesday, or another day could work.

Another example is:

You can call me any day after Monday.

This means the person is available on whichever day the caller chooses after Monday.

The phrase can also describe something that may happen at an unknown time in the near future.

The package should arrive any day now.

In this sentence, “any day now” suggests that the package is expected very soon, although the exact day is unknown. This is a common English expression.

Why Is “Anyday” Usually Considered Incorrect?

One reason people write “anyday” is that English contains many similar-looking words that are correctly written as one word.

For example:

• anyone
• anything
• anywhere
• anytime
• everyday
• someday

Because these words exist, it can seem logical to assume that “anyday” should also be a single word. However, English spelling does not always follow a predictable pattern.

The fact that one combination has become an established compound word does not automatically mean another similar combination should be joined. “Any day” remains a two-word expression in standard English. Grammar and usage references generally recommend keeping the words separate.

Any Day in Everyday Sentences

The easiest way to understand the correct form is to see it in natural sentences.

Here are some examples:

I can finish the project any day this week.

This means that the speaker is flexible about the day.

You can come over any day you like.

The listener may choose whichever day is convenient.

The weather could change any day.

The exact day when the weather changes is unknown.

We might receive the results any day now.

This means the results are expected soon.

She is available any day except Friday.

The person can meet on several days, but Friday is excluded.

In each sentence, “any” modifies the noun “day,” so the two words remain separate.

The Meaning of “Any Day Now”

One of the most common expressions containing “any day” is “any day now.”

This phrase means that something is expected to happen very soon.

For example:

The baby could arrive any day now.

Our new furniture should be delivered any day now.

The company may announce the decision any day now.

The exact timing is uncertain, but the event is expected in the near future.

This expression is especially useful in everyday conversations because it communicates uncertainty while also suggesting that something is likely to happen soon.

Any Day vs Every Day

Another reason people confuse “any day” with “anyday” is the word “everyday.”

However, “every day” and “everyday” have different grammatical functions.

Every day means each day.

Example:

I exercise every day.

Here, “every day” tells us how often the action happens.

Everyday is an adjective meaning ordinary, usual, or common.

Example:

These are my everyday shoes.

The shoes are used regularly or for ordinary activities.

The same pattern should not be applied automatically to “any day.” While “everyday” is an established adjective, “anyday” is generally not accepted as the standard form for the ordinary uses of “any day.”

Common Mistakes With Any Day

Many mistakes happen because writers type quickly or rely on how a word sounds. Since there is no audible space between “any” and “day,” it is easy to combine them when typing.

Here are some common errors:

Incorrect: I can meet you anyday.

Correct: I can meet you any day.

Incorrect: The delivery should arrive anyday now.

Correct: The delivery should arrive any day now.

Incorrect: You can choose anyday that works for you.

Correct: You can choose any day that works for you.

Incorrect: Call me anyday after six.

Correct: Call me any day after six.

The correction is simple: separate “any” and “day.”

Is “Anyday” Ever Seen in Writing?

Yes, you may occasionally encounter “anyday” online. People sometimes use it in text messages, comments, social media posts, and other informal communication. Some writers may also use it deliberately as a casual or stylistic spelling.

However, seeing a form online does not necessarily mean that it is considered standard English.

If you are writing an essay, article, business email, school assignment, website page, report, or other formal material, “any day” is the safer choice.

Some usage references note that “anyday” can appear informally, but recommend keeping the words separate in formal writing.

How to Remember the Correct Spelling

A simple memory trick can help you remember the difference.

Think about what “day” means in your sentence. If you are referring to a possible calendar day, keep “any” and “day” separate.

For example:

I can visit any day.

You could also mentally expand the phrase:

I can visit on any day.

Because “day” is clearly functioning as a noun, the two words stay separate.

Another useful technique is to compare it with a phrase such as “every day”:

• any day = any possible day
• every day = each day
• everyday = ordinary or usual
• someday = at an unspecified time in the future

Seeing these differences together makes the spelling easier to remember.

Any Day in Formal Writing

Correct word choice becomes particularly important in formal communication. A spelling mistake may seem small, but repeated errors can affect how professional your writing appears.

Imagine writing:

The manager is available anyday next week.

The reader can understand the sentence, but the spelling may make the document look less polished.

The improved version is:

The manager is available any day next week.

The change is tiny, but it follows standard usage and creates a cleaner impression.

This matters when writing resumes, cover letters, academic assignments, professional emails, website content, and business documents.

Any Day vs Anyday: A Simple Comparison

Form	Standard English	Typical Meaning	Example
Any day	Yes	Any possible day	I can meet any day.
Anyday	Generally no	Nonstandard spelling	Avoid it in formal writing.

The main rule is therefore easy: use “any day” as two words.

Final Thoughts

The difference between “any day” and “anyday” may look minor, but it is an important spelling and usage point. In standard English, “any day” is the correct form when you mean an unspecified day, any possible day, or a day that could be selected from several choices.

Remember that “anyday” sometimes appears in informal online communication, but it is generally not the preferred form for standard or professional writing.

Whenever you are unsure, keep the words separate: any day.

Whether you are writing a school assignment, professional email, blog post, or casual message, using the standard form will make your writing clearer and more polished. Once you learn this simple rule, choosing between “any day” and “anyday” becomes much easier.