Weekly or fortnightly pay is common in Australia, so talking about it as weeks of pay made sense to me. I don't think they really even use the term "fortnight" in the US. Every tech company I've worked at here seems to do the 15th and 30th which is still strange to me.
It's true, I have colleagues point out how odd my usage of fortnight is in presentations, meetings, etc. Had no idea that was a difference until I moved stateside.