The terms biweekly and semimonthly are often used interchangeably, but they actually represent two distinct types of frequency in time. Both describe how frequently a particular event occurs, such as pay periods, meetings, or other recurring events. The main difference is the number of occurrences over a specific period, typically a year.
Biweekly refers to an event or action that takes place every two weeks or every 14 days. In other words, biweekly events occur twice a month, but the exact number of occurrences may vary depending on the number of days in a month. Over the course of a year, biweekly events will happen 26 times, since there are 52 weeks in a year. The reason for this is because 52 weeks divided by 2 equals 26. In the case of pay periods, for example, a biweekly pay schedule would result in an employee receiving 26 paychecks per year.
Semimonthly, on the other hand, refers to an event or action that occurs twice per month or every half-month. Unlike biweekly, semimonthly events occur at regular intervals, typically on specific dates, such as the 1st and 15th or the 15th and the last day of the month. This means there will always be 24 occurrences of a semimonthly event in a year, regardless of the number of days in a month. Using the pay period example again, a semimonthly pay schedule would result in an employee receiving 24 paychecks annually.
The choice between the two often depends on the context and the specific needs of the organization or individual involved. For instance, employers might choose a biweekly pay schedule to simplify payroll calculations or a semimonthly schedule to align with other monthly expenses and bills.