The quick answer: A fortnight is two weeks or 14 days.
There are 26 fortnights in a year.
There are 336 hours in a fortnight.
There are 20,160 minutes in a fortnight.
It’s an Old English word, fēowertyne niht, which literally means fourteen nights.
The word fortnight is most commonly used in the UK and its colonies. It is not that common in the US, where people tend to use the term two weeks in reference to that period of time; for example, “The 4th of July is in two weeks’ time.”
People use “a fortnight’s time” or “in a fortnight” to refer to an event that will happen in two weeks; for example, “We’re going on holiday in a fortnight,” or, “The new Stephen King book will be out in a fortnight’s time”.
People use “fortnightly” to refer to something that occurs regularly every two weeks; for example, fortnightly wages.
Wages tend to be paid weekly or on a fortnightly basis. Salaries tend to be paid monthly.
Some countries have a different number of days in a fortnight. Perhaps, more correctly, they use a 15-day period instead of 14 days.
For example, the Welsh use pythefnos, which means 15 nights. Greeks use dekapenthímero, which also means 15 days.
France, Italy, Portugal, Spain, and Romania all use terms that refer to 15 days.
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