Here’s what you’ll find: Biweekly means once every two weeks or twice a week. Bimonthly means once every two months or twice a month. In addition, a biweekly publication is issued every two weeks and a bimonthly publication is issued every two months. Semiweekly means twice a week. Semimonthly means twice a month. To avoid confusion, you may want to substitute the actual time frame for these confusing terms.