Fortnight-Year

A span of time that's just like a fortnight, but in years and not weeks.

I've been trying to talk to you for a fortnight-year, and now I've got your attention.
This guy has spent a fortnight-year, cheating on his girlfriend, and not telling her anything about it.

Fortnight-Year

A period of time that spans 2 years.
To put this into perspective, a fortnight is a span of two weeks and this is just like that, but for years (not weeks).

It's been about a fortnight-year ago, since you broke up with me, do you want to make up now?
This guy has been cheating on his girlfriend for a fortnight-year, and it's only now that I've realized that fact.