While “monthly” is a universal concept, its rhythm is particularly dominant in the structure of modern Chinese life. In China, the month is the primary unit for organizing one's economic life. Salaries (工资 - gōngzī) are almost universally paid on a monthly basis. Rent (房租 - fángzū) and utility bills are also settled monthly. Therefore, understanding and using 每月 is essential for handling basic personal finances and planning. This contrasts slightly with some Western cultures where bi-weekly pay cycles can be common. In China, the monthly salary cycle is deeply ingrained in professional and personal life, making 每月 a word you'll hear and use daily. The character 月 also carries the beautiful dual meaning of “moon,” a subtle echo of the lunar calendar (农历 - nónglì) which, while not used for business, still governs traditional holidays and cultural events, linking modern schedules to ancient traditions of timekeeping.
每月 is a neutral term that works in both formal and informal situations. It's concise and efficient.
It's slightly more formal and common in writing than its colloquial cousin, `每个月 (měi ge yuè)`. While they are largely interchangeable in speech, you are more likely to see 每月 in a contract, official notice, or news headline.