semimonthly

Semimonthly is an adjective describing something that occurs twice in a month, or once every half month. In practice, it typically means two occurrences per calendar month, often on regular dates such as the 1st and 15th or the 15th and the last day. The term is sometimes written as semi-monthly or hyphenated as semi-monthly, though semimonthly is common in American usage. The etymology combines semi- meaning half with monthly, indicating occurrence in halves of a month.

In payroll and publishing contexts, semimonthly schedules are common. A semimonthly payroll yields 24 pay periods per year, in contrast to a biweekly schedule, which produces about 26. Because calendar months vary, semimonthly dates can shift with months of different lengths, but the intended frequency remains two per month. Semimonthly publications may release two issues per month, not necessarily on fixed weeks.

Relation to other terms: biweekly means every two weeks, which can result in 26 pay periods per year and does not align exactly with calendar months. Bimonthly can be ambiguous, meaning either every two months or twice a month. When precision matters, it is better to specify dates or the number of occurrences per year rather than rely on these terms.

Usage notes: in contracts or official policies, define the schedule explicitly (for example, pay on the 15th and the last day of each month) to avoid confusion.