A fortnight is a unit of time equal to 14 days (2 weeks). The word derives from the Old English: fēowertyne niht, meaning "fourteen nights".[1][2]

Some wages and salaries are paid on a fortnightly basis;[3] however in North America it is far more common to use the term biweekly. Neither of these terms should be confused with semimonthly, which divides a year into exactly 24 periods (12 months × 2), instead of the 26 (≈52 weeks ÷ 2) of fortnightly/biweekly.[4]


For more information see eclipse cycle.

In astronomy, a fortnight is half a synodic month, equivalent to the mean time between a full moon and a new moon (and vice versa). This is equal to 14.77 days.[5][6]

Other Languages
català: Quinzena
español: Quincena
日本語: 半月 (期間)
português: Quinzena
русский: Фортнайт
తెలుగు: పక్షము
ไทย: ปักษ์