every 3rd hour

USAGE SUMMARY

The phrase "every 3rd hour" is correct and usable in written English.
It can be used to indicate a recurring event or action that takes place at intervals of three hours. Example: "The train departs every 3rd hour, so make sure to check the schedule for the next departure."

✓ Grammatically correct

Science

Human-verified examples from authoritative sources

Exact Expressions

1 human-written examples

We will thus give 75 μg clonidine every 3rd hour up to a maximum of 4 doses on day 1, and then 75 μg twice per day.> Concentration levels of clonidine known to have clinical effects range from 0.2 to 2.0 ng/ml [ 50- 52].

BMC Geriatrics

Human-verified similar examples from authoritative sources

Similar Expressions

59 human-written examples

Spacecraft positions at every 1 hour are indicated by crosses.

Earth, Planets and Space

Most coaches charge $25-$25-$45ry 1/2 hour.

WikiHow

It's actually 100m, every 24 hours.

The Guardian - Lifestyle

"But every 12 hours someone gets MND in Australia, and every 12 hours someone dies.

The Guardian - Sport

He was permitted four hours sleep every 16 hours.

The Guardian

The goal is to empty every toilet every 24 hours.

The New York Times

The 1 million patient interactions every 36 hours.

The Guardian

"That's 12 children killed by guns every 24 hours.

The New York Times

A rhinoceros is killed every 11 hours.

BBC

Patients were given 50 μg misoprostol every 4 hours.

American Journal of Obstetrics and Gynecology

Expert writing Tips

Best practice

When using the phrase "every 3rd hour" in scientific or medical contexts, ensure that it's clear whether the time interval starts from a specific point or is a continuous cycle. For clarity, specifying the starting point is often beneficial.

Common error

A common mistake is assuming a universally understood starting point for the "every 3rd hour" interval. Always clarify the origin of the time cycle (e.g., "starting at midnight") to prevent confusion, especially in time-sensitive protocols.

Linguistic Context

The phrase "every 3rd hour" functions as an adverbial phrase, modifying a verb by specifying the frequency or interval at which an action occurs. It indicates how often something is done, as exemplified by Ludwig in the context of medication administration.

Expression frequency: Rare

Frequent in

Science

100%

Less common in

News & Media

0%

Formal & Business

0%

Wiki

0%

Ludwig's WRAP-UP

In summary, "every 3rd hour" is a grammatically correct adverbial phrase used to specify that an action or event occurs at three-hour intervals. Ludwig's AI confirms its usability, while examples show its prevalent use in scientific and medical contexts. Though rare in broader contexts, its precise meaning makes it suitable for situations requiring exact timing. For general communication, "every three hours" is more commonly used, ensuring clarity and wider acceptance. When clarity and accuracy are paramount, as in medical or scientific instructions, its specific application is beneficial.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

every three hours

Replaces the ordinal "3rd" with the cardinal "three", offering a more common phrasing.

every third hour

Uses the full ordinal "third" instead of the abbreviation "3rd".

once every three hours

Adds emphasis on the single occurrence within the three-hour period.

each three hours

Replaces "every" with "each" maintaining a similar structure.

at three-hour intervals

Shifts the focus to the interval itself rather than the frequency.

trihourly

A single-word adjective that means occurring every three hours.

three hours apart

Emphasizes the separation in time between events.

every 180 minutes

Converts the time frame to minutes for greater precision.

with a three-hour frequency

Nominalizes the phrase, highlighting the frequency as a characteristic.

at the third hour

Focuses on a specific hour within a cycle.

FAQs

How can I rephrase "every 3rd hour"?

You can use alternatives such as "every three hours", "once every three hours", or "at three-hour intervals" depending on the context.

Is it better to write "every 3rd hour" or "every third hour"?

Both "every 3rd hour" and "every third hour" are acceptable, but "every three hours" is generally preferred for clarity and common usage. The abbreviated form is more suitable for technical documentation where brevity is valued.

What does "every 3rd hour" mean?

The phrase "every 3rd hour" means that something occurs or should be done at intervals of three hours. For example, medication might be administered "every 3rd hour".

In what situations is it appropriate to use "every 3rd hour"?

It's appropriate to use "every 3rd hour" in situations where a task, event, or action needs to be repeated at consistent three-hour intervals. This is common in medical settings (medication), scientific experiments (data collection), or industrial processes (quality checks).