“Fortnight” is such an interesting word. It’s still used in British English, but it sounds anachronistic to American ears, like “four score.” If it sounds like it’s a blend of the two words “fourteen” and “night”, that’s because it very much is. Fourteen nights, or two weeks, is the length of time in one fortnight.
The only time the word "fortnight" is used in our house is when my son tells us he can't wait to be a teenager so he can play "Fortnite"
How about "Fartnite"? If you have a preteen son, I would hope for this to become a thing at some point.
That's exactly the kind of dad humor he's come to (rightfully) expect from me by now.
That's doing things right.