Ed Huntress fired this volley in
:

I don't know about that "rule of thumb," Lloyd, but concrete hardens
best when it's completely under water. You don't want it to dry at
all. And the surface should harden even when it's soaking wet, if the
mix wasn't too wet to begin with.

You don't read, do you, Ed?

What about "six days' WET cure" didn't you understand?
The surface will not become durable until it dries, but it has to cure
throughout first.

Pay attention. You might learn something -- like how to read.

Lloyd