Nighttime or Night Time? Correct Spelling and Examples
See when to write nighttime as one word, how night time appears in writing, and simple examples that make the distinction clear.
Nighttime or Night Time? Correct Spelling and Examples
Nighttime is the standard one-word noun in American English when you mean the part of a day associated with night. Night-time also appears as a hyphenated form in some varieties of English and editorial styles. The open form, night time, can appear in ordinary writing, but for a consistent US-English article or label, nighttime is usually the cleanest choice.
The quick spelling answer
Write nighttime for a noun or modifier describing the hours of darkness: “The temperature drops at nighttime” or “The nighttime schedule is different.” Many publications also prefer “at night,” which often sounds shorter and more natural than “at nighttime.”
If you are choosing a spelling for an American website, use the one-word form in headings, category labels, and repeated references. Consistency helps readers and avoids creating two versions of the same terminology across pages.
Is nighttime one word in American English?
Yes. Major American dictionaries record nighttime as one word. It refers to night or the hours when it is night. Some edited British-English texts may prefer night-time, so the existence of a hyphenated version does not automatically make the text incorrect. The best choice depends on the publication's style guide and audience.
Here are practical sentence examples:
| Sentence | What to notice |
| “Nighttime temperatures can fall quickly.” | One-word adjective-like modifier before a noun |
| “The street is quiet at nighttime.” | One-word noun referring to the period |
| “We usually walk the dog at night.” | Often the most natural everyday alternative |
| “The sign lists nighttime parking restrictions.” | Consistent US-English wording |
In some contexts, “the time of night” is clearer than either form. For example, “What time of night did the alarm sound?” asks for a specific hour, not the general period called nighttime.
When should you write “night time” as two words?
The open spelling may appear in informal messages or when someone intends two separate words. But it is generally less standardized than nighttime in US editorial prose. If you are editing a business page, product manual, or guide, keeping the one-word form makes the text more consistent.
Avoid overcorrecting genuine phrases such as “night time slot” without checking the grammar. Often the best revision is not to debate the compound at all: “an overnight slot,” “the 10 p.m. shift,” or “a nighttime appointment” can each communicate a different nuance more clearly.
Nighttime versus night: is the meaning different?
The two words overlap. Night is the everyday noun with a wide range of meanings, including the interval of darkness, a calendar night, and a social occasion (“a night out”). Nighttime focuses more narrowly on the period associated with night. It may be especially useful when contrasting daytime and nighttime conditions.
For example, “This plant opens at night” sounds direct and natural, while “The study compares daytime and nighttime temperatures” emphasizes two categories. Neither sentence establishes when darkness begins at a particular location.
If you actually want to know what time night begins, that is a separate question involving sunset and twilight. For word choices that are close in meaning, see night synonyms.
Common mistakes to avoid
First, do not treat a spelling question as a reason to invent fixed nighttime hours. An editor can choose nighttime while acknowledging that time boundaries vary. Second, avoid using nighttime when you need a specific deadline: “Submit by 11 p.m.” is clearer than “Submit by nighttime.” Third, watch for needless repetition. “Nighttime activities at night” can be shortened to “nighttime activities.”
Also check whether the sentence works better with overnight, which usually means through the night or lasting until the next day. “An overnight delivery” is not the same as “a nighttime delivery,” and the distinction may matter operationally.
Frequently asked questions
Is nighttime one word or two?
In standard US-English writing, nighttime is commonly one word. The hyphenated form night-time is also encountered in other editorial conventions.
Is “night time” incorrect?
It can occur in informal writing, but one-word nighttime is the safer and more consistent default for American editorial prose.
Is nighttime an adjective?
It can function as a modifier before a noun, as in “nighttime traffic,” although dictionaries commonly list it as a noun.
Is nighttime the same as overnight?
Not exactly. Nighttime names a period; overnight often means lasting through the night or occurring between one day and the next.