It certainly sounds like it really depends on how one defines “build”.
It reminds me of the Liberty Ships in WWII. At first, they took months to build. By the end of the war, they had that down to just over a month.
In one case, a publicity stunt, they went from laying down the keel to launching in under 5 days. But that was definitely a publicity stunt. There were several bits internally that needed to be finished after, and they had everything prepped and ready ahead of time.
There are several plausible ways of defining “build” that would allow for something like this. Does that mean they could build a supercomputer from scratch, on demand, anywhere in the world in 19 days, including preparing the building, power, permitting, etc? Almost certainly not.
But it got you talking about it, right? And that’s the actual purpose.