every third hour

USAGE SUMMARY

The phrase "every third 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 medication should be taken every third hour to maintain its effectiveness."

✓ Grammatically correct

Science

News & Media

Human-verified examples from authoritative sources

Exact Expressions

9 human-written examples

Every third hour, you squeeze a Monopoly-race-car-sized amount onto the tips of your fingers (right hand), and then dab your ends with it.

The New Yorker

N = 34 professional driver students drove in a high-fidelity driving simulator at 80 km/h for 55 min every third hour during 36 h of sustained wakefulness.

Accident Analysis & Prevention

Eight blood samples were drawn each day (every third hour) on 8 days of the protocol and analyzed with respect to IL-6 and TNF-α.

Brain, Behavior, and Immunity

The occurrence of aggressive behaviour, play behaviour and synchronous resting was recorded throughout the day (i.e. every third hour for 15 min during 24 h) on day 1, day 5, day 19 and day 33 after mixing.

Applied Animal Behaviour Science

The perfusate was collected every third hour.

Critical Care

Clinical status was taken every third hour 24 48 hours postoperatively, or longer if needed.

Acta Veterinaria Scandinavica

Human-verified similar examples from authoritative sources

Similar Expressions

51 human-written examples

CSF and blood samples were obtained every second hour during a 16-hours study period and were analyzed for bacterial concentrations by quantitative cultures (lower detection level: 50 CFU/ml) and WBC on an automatic cell counter (Swelab, Åstad, Sweden).

BMC Infectious Diseases

Consecutive sampling of aldehydes every eighth hour as well as total aldehyde sampling was performed during the first 5 days after application of the paints.

Industrial Crops and Products

Urinary output was measured, and urine samples from both kidneys were collected at baseline, after 90 min and thereafter every second hour.

Intensive Care Medicine Experimental

Imagine a job that only paid you for every second hour you worked and threatened to have you kicked out of the country if you complained.

Vice

After cell cycle arrest by serum-starvation, BrdU was incorporated for 1 h in serum-rich medium after which cells were harvested every second hour.

Plosone

Expert writing Tips

Best practice

When describing medical or scientific protocols, use "every third hour" to specify the timing of interventions or measurements for clarity and precision.

Common error

Avoid using "every third hour" when you mean something lasts for three hours. Use it only to indicate actions repeating at three-hour intervals, not for continuous durations.

Linguistic Context

The phrase "every third hour" functions as an adverbial phrase of frequency, specifying how often an action or event occurs. As shown by Ludwig's examples, it is frequently used in scientific contexts to describe measurement or treatment intervals.

Expression frequency: Uncommon

Frequent in

Science

75%

News & Media

20%

Formal & Business

0%

Less common in

Encyclopedias

0%

Wiki

0%

Reference

0%

Ludwig's WRAP-UP

In summary, "every third hour" is a grammatically sound phrase used to denote events occurring at three-hour intervals. Ludwig confirms its correctness and shows it is most commonly found in scientific and medical contexts, where precise timing is essential. While not as common as "every three hours", it serves the same purpose effectively. When writing, ensure it accurately reflects intended frequency and avoid confusing it with duration. The phrase is formal and best suited for technical or instructional content.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

every three hours

Replaces "third" with the numerical equivalent; slightly more direct.

once every three hours

Adds emphasis on the frequency of the event.

at three-hour intervals

Focuses on the gap between occurrences, rather than the sequence.

every 180 minutes

Provides the interval in minutes, making it more precise.

trihourly

Uses a single-word adjective to describe frequency; more formal.

every span of three hours

Emphasizes the duration between each action or event.

on a three-hour schedule

Highlights that the actions or events are part of a planned routine.

three hours apart

Indicates the temporal separation between occurrences.

every third of a day

Relates the timing to a fraction of a day.

with a three-hour periodicity

Emphasizes the cyclical nature of the occurrences; more technical.

FAQs

How can I use "every third hour" in a sentence?

Use "every third hour" to indicate something that happens repeatedly with a three-hour interval. For example, "The medication should be administered "every third hour"."

What is a more common way to say "every third hour"?

A more common alternative is to say "every three hours". It conveys the same meaning but is often considered more straightforward.

Is it better to use "every third hour" or "every three hours"?

Both "every third hour" and "every three hours" are grammatically correct. The choice depends on stylistic preference; "every three hours" is generally more common.

What's the difference between "every third hour" and "every other hour"?

"Every third hour" means something happens, then there's a two-hour gap before it happens again. "Every other hour" means it happens, then there's a one-hour gap.