Fortnight

A fortnight is a period of fourteen nights. Owing to an administrative oversight in the Middle Ages, it also contains fourteen days, which were slipped in between the nights and have never been formally removed.^[1]

A fortnight is two weeks long, which makes it exactly the same length as two weeks, but noticeably more old-fashioned.

Origin

The word comes from the Old English for “fourteen nights”, because people at the time counted in nights, having slept through most of the days. The days were only discovered in 1340, when a clerk reviewing the calendar found them hidden between the nights and filed a report. The report was read a fortnight later, in 1611.^[2]

Usage

The fortnight is used mainly for paydays, holidays and the phrase “I’ll get back to you in a fortnight”, which is the longest unit of time in the English language. Of fortnights promised in this way, 8% last fourteen days, 31% last a month and 61% are still in progress.^[3]

• One fortnight: two weeks.
• Half a fortnight: one week, but in a waistcoat.
• A quarter of a fortnight: three and a half days, which nobody has ever needed.
• A fortnight of Mondays: two Mondays, which is plenty.

See also

• Week – half a fortnight, no waistcoat
• Tomorrow – always the first day of the next fortnight
• Time – what fortnights are made of
• Year – about 26 of them

References

1. Vellum, T. (1340). “Report on Some Days Found in the Calendar”. Read 1611.
2. Bureau of Weekdays (2026). “Two of Them: The Fortnight Explained”.
3. Later, I. (2019). I’ll Get Back to You. Unfinished.