Bimonthly vs. Biweekly – Which is Correct?

While both terms relate to frequency, biweekly means happening every two weeks. Bimonthly, however, is ambiguous and can mean either twice a month or every two months. For clarity, it’s best to specify “twice a month” or “every two months” instead of using bimonthly.

Bi Monthly or Biweekly – Which is Correct?

The core distinction between “bi monthly” (more commonly written as bimonthly) and biweekly lies in their precise timing. Both are valid terms, but bimonthly suffers from significant ambiguity, leading to frequent misunderstandings. Biweekly is straightforward, consistently referring to an event occurring every two weeks.

The confusion with bimonthly stems from the prefix “bi-,” which can mean “two” or “every two.” Thus, bimonthly can logically be interpreted as “twice a month” or “every two months.” Because of this inherent vagueness, careful writers and communicators often avoid bimonthly in favor of more explicit phrasing like “twice a month” or “every other month” to prevent misinterpretation.

Word	Part of Speech	Meaning	Example
Bimonthly	Adjective/Adverb	Happening twice a month OR happening every two months.	The bimonthly newsletter (could be twice a month or every two months).
Biweekly	Adjective/Adverb	Happening every two weeks.	Employees receive their salaries on a biweekly basis.

How to Use Bimonthly

The term bimonthly can function as both an adjective and an adverb. When used, it describes something that occurs either twice within a month or once every two months. Due to this inherent ambiguity, it is generally advisable to use more specific language, especially in formal or business contexts where precision is critical. If you must use it, ensure the context makes the intended meaning absolutely clear, or be prepared to clarify.

Example 1: The club publishes a bimonthly magazine, which some members expect twice a month, while others think it’s every two months.

Example 2: Our team holds bimonthly meetings, alternating between the first and third week of the month.

Example 3: The financial report is released bimonthly, meaning six times a year, in February, April, June, August, October, and December.

What are the different forms of Bimonthly?

Bimonthly primarily exists in its adjective/adverb form. It doesn’t typically have different tenses or pluralizations in the way verbs or nouns do. It can sometimes be hyphenated as “bi-monthly,” but the single-word form is more common. The key “forms” relate more to its ambiguous meaning than grammatical variations.

Etymology of the word Bimonthly

The word bimonthly is derived from the Latin prefix “bi-” meaning “two” or “twice,” combined with the Old English word “month” (from Latin mensis). The ambiguity arises from the dual interpretation of “bi-” as “twice per period” or “every two periods,” a characteristic it shares with other “bi-” prefixed words like biannual.

This dual interpretation of ‘bi-‘ also creates similar confusion in terms like biennial versus biannual, where precise usage is equally important.

How to Use Biweekly

The term biweekly is much less ambiguous than bimonthly. As an adjective or adverb, it consistently means “occurring every two weeks.” This makes it a reliable choice when describing events, payments, or schedules that adhere to a fourteen-day cycle. It is widely understood and commonly used in various professional and casual settings without causing confusion.

Example 1: The company processes payroll on a biweekly schedule, ensuring employees are paid every other Friday.

Example 2: We have a biweekly check-in with our remote team to discuss project progress.

Example 3: Her subscription delivers fresh produce biweekly, arriving on alternate Tuesdays.

What are the different forms of Biweekly?

Similar to bimonthly, biweekly primarily functions as an adjective or adverb. It does not have significant grammatical variations like tenses or plural forms. It can sometimes appear hyphenated as “bi-weekly,” but the unhyphenated form is prevalent and widely accepted.

Etymology of the word Biweekly

Biweekly also traces its roots to the Latin prefix “bi-” meaning “two” or “twice,” combined with “weekly” (from Old English wice). In this case, the “bi-” clearly refers to “every two” rather than “twice within the period,” likely due to the established understanding of “weekly” as a singular period.

Related Concepts

Understanding the prefixes “bi-” and “semi-” can greatly clarify terms related to frequency. “Bi-” (as seen in bimonthly and biweekly) implies “two” or “every two.” The confusion arises because it can mean “twice within a period” (e.g., bimonthly meaning twice a month) or “every two periods” (e.g., bimonthly meaning every two months, or biweekly meaning every two weeks). In contrast, “semi-” consistently means “half” or “partially,” and when used with time, it usually means “twice within the period.” For instance, semimonthly means twice a month, and semiannual means twice a year. Using “semi-” can often be a clearer alternative when you intend to convey “twice a period” rather than “every two periods.”

Examples from Media and Literature

• “The newspaper was published biweekly, a reliable source of local news appearing every other Wednesday.”
• “Their committee’s bimonthly report was always a point of contention, as no one was ever sure if it covered two months or simply came out twice a month.”
• “He preferred a biweekly haircut, finding that every two weeks was the perfect interval to maintain his style.”
• “The literary journal, released bimonthly, aimed to showcase emerging talent six times a year.”
• “The payroll department ensured all employees received their biweekly statements promptly.”

Practice Exercises

Choose the correct word to complete the sentence.

1. The company’s performance reviews are held on a __________ basis, occurring every two weeks.
2. Our club’s __________ newsletter is published twice a month, so members receive twelve issues annually.
3. Employees are paid __________ on the first and fifteenth of each month.
4. The art gallery hosts a new exhibition __________ every two months, with six shows per year.
5. For maximum clarity, it’s best to specify “every two weeks” rather than using the ambiguous term __________.

Answer Key

1. biweekly
2. bimonthly (or semimonthly for clarity)
3. semimonthly (or twice a month for clarity)
4. bimonthly (or every two months for clarity)
5. bimonthly

Bimonthly Synonyms

Synonym	Definition
Twice a month	Occurring two times within a single month.
Every two months	Occurring once every sixty days.
Semimonthly	Occurring twice a month (a clearer alternative for one meaning of bimonthly).

Biweekly Synonyms

Synonym	Definition
Every two weeks	Occurring once every fourteen days.
Fortnightly (British English)	Occurring every two weeks.
Every other week	Occurring on alternating weeks.

Frequently Asked Questions

Question 1: What is the main difference between bimonthly and biweekly?
The main difference is that biweekly consistently means “every two weeks,” while bimonthly is ambiguous, meaning either “twice a month” or “every two months.”

Question 2: Which term should I use for clarity?
For clarity, it is always best to use biweekly when you mean “every two weeks.” When you mean “twice a month,” use “twice a month” or semimonthly. When you mean “every two months,” use “every two months.”

Question 3: Are “bi-monthly” and “bimonthly” the same?
Yes, “bi-monthly” (hyphenated) and “bimonthly” (one word) are generally considered interchangeable and carry the same ambiguous meanings. The single-word form is more common in modern usage.

Conclusion

In summary, while both bimonthly and biweekly refer to frequencies, biweekly offers clear, unambiguous communication, consistently meaning “every two weeks.” Bimonthly, however, is fraught with ambiguity, capable of meaning either “twice a month” or “every two months.”

Pro Tip: To maintain professionalism and avoid miscommunication, especially in business or formal contexts, opt for precise phrasing. Instead of bimonthly, specify “twice a month,” “every two months,” or “semimonthly.” This ensures your audience understands your intended schedule without confusion, safeguarding your professional reputation.