by day

USAGE SUMMARY

'by day' is correct and usable in written English.
It is used to refer to the amount of activity that happens during the day as opposed to at night. For example, "Sales were slow by day, but picked up significantly at night."

✓ Grammatically correct

News & Media

Science

Encyclopedias

Human-verified examples from authoritative sources

Exact Expressions

57 human-written examples

Skimmers (Rynchopidae) feed by day or night.

Encyclopedia Britannica

Sam day by day".

The Guardian - Lifestyle

By day, a political idealist.

The Guardian - Film

You live day by day.

The Guardian

Standards improving day by day.

The Guardian

"By day, I'm Norm Swissel.

The New Yorker

By day 6, this finding was reversed.

Journal of Orthopaedic Research

All controls healed by day 14.

Otolaryngology - Head and Neck Surgery

Human-verified similar examples from authoritative sources

Similar Expressions

3 human-written examples

"He's a day-by-day decision.

Los Angeles Times

"It's a day-by-day process".

The New York Times

World Athletics day-by-day guide.

BBC

Expert writing Tips

Best practice

When contrasting activities that occur at different times, use "by day" to clearly distinguish daytime actions from those that happen at night or another specific time. For example, "By day, she works as a teacher; by night, she writes novels."

Common error

Avoid using "by day" when simply describing a daytime activity without contrasting it with another time or activity. Saying "I work by day" is less precise than "I work during the day" if there's no implied comparison to nighttime activities.

Linguistic Context

The phrase "by day" functions primarily as an adverbial phrase, modifying verbs or clauses to specify when an action occurs. As seen in Ludwig examples, it often provides a temporal context, contrasting daytime activities with those at other times.

Expression frequency: Very common

Frequent in

News & Media

66%

Science

20%

Encyclopedias

2%

Less common in

Formal & Business

0%

Wiki

0%

Reference

0%

Ludwig's WRAP-UP

In summary, the phrase "by day" is a common and grammatically sound way to specify that an activity or state occurs during the daytime. As Ludwig AI explains, it is often used to contrast daytime activities with those at night. It's important to use "by day" when such a contrast is intended, rather than simply describing a daytime occurrence. The phrase appears frequently in news and media, science, and encyclopedic contexts, affirming its versatility. For alternatives, consider using "during the day" or "in daylight hours" to convey similar meanings.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

during the day

This alternative directly replaces "by day" with a more common prepositional phrase indicating the same time frame.

in the daytime

This phrase uses a noun form to refer to the period between sunrise and sunset.

throughout the day

Similar to "during the day", this alternative implies a continuous action or state from morning to evening.

each day

This alternative emphasizes the repetition of an event or state on a daily basis.

in the course of the day

This phrase highlights events or activities that happen at some point during the day.

in daylight hours

This phrase emphasizes the time when natural light is present, providing a slightly more specific context.

on a daily basis

A more formal way of saying "each day", suitable for business or academic contexts.

daily

This single-word adjective can replace "by day" when describing routines or occurrences that happen each day.

during the working day

This alternative specifies the daytime period during which people are typically at work.

from morning to night

This emphasizes the entirety of the day, from its beginning to its end.

FAQs

How can I use "by day" in a sentence?

Use "by day" to specify an activity or state that occurs during the daytime, often in contrast to something else. For example, "By day, the city is bustling; by night, it's quiet."

What's a simple substitute for "by day"?

A simple substitute for "by day" is "during the day", which conveys the same meaning without implying a contrast. The two can be interchangeable depending on the context.

Is "by day" formal or informal?

"By day" is considered neutral in formality. It can be used in both formal and informal contexts, although phrases like "during daylight hours" might be preferred in more formal writing.

How does "by day" compare to "day by day"?

"By day" refers to activities happening during the daytime, whereas "day by day" refers to a gradual process or change over consecutive days. They have distinct meanings and cannot be used interchangeably.