You forgot the "assuming requirements don't change" part.

What's actually heard would be "Wa wa wah (up to) six months from now (guaranteed) wa wa."

Yeah, and they'll push for four months total at a meeting a month into the project, while simultaneously changing their mind on a half dozen requirements.

Ugh. I was on a project like this. I figured that it was mostly just that specific customer...

...Unfortunately, there's a lot of "specific customers" like this.