How Long Do You Suppose?

From the first time you see the teeny head of a leaf poking from the center of the rosette, how long apporoximatly does it take for the jaws to open to be fed? Obviously, there are some factores in place, but say, in average conditions. Not the BEST, but fairly decent...

I would say 'average' if everything was right...2-3 weeks. I don't really think that they take that long (for me ), but that should be a safe guess