Once a fortnight

What’s a fortnight? I got a commission this morning from a newspaper with a deadline of “Monday fortnight”. Eh? Is that a week from Monday, or two weeks from Monday, or a fortnight from next Monday? Exactly what is a fortnight anyway?

Well, according to Wikipedia, that fountain of all human knowledge(!)

A fortnight is a unit of time equal to two weeks: that is 14 days, or literally 14 nights. The term is common in the British Isles and many Commonwealth countries, but rarely used in the United States. It derives from the Old English feowertiene niht, meaning "fourteen nights".

Breakdowns

* 1 fortnight = 2 sennights (or two weeks)
* 1 fortnight = 336 hours
* 1 fortnight = 20,160 minutes
* 1 fortnight = 1,209,600 seconds

So there you go, that's what a fortnight is.