Actually, and take this with a grain of salt, I have a different opinion about this.

Stay with me, here.

I'd start with pants. Add the kilt later, once kids get used to you, and you are just part of the background. It'll be easier on them, and on you.

As for a time frame, wait until after Halloween.

Now, at the risk of offending the kilt cops, I reiterate that kilts are just clothes, and there is an appropriateness to every kind of clothing. One wears a swim suit to swim, not to dinner; a tux to formal events, not to grill meat with.

For kindergarteners, who are starting a brave new world, sticking out is good after the initial entrance into a larger social environment. Once they have found their niche, sticking out, or having dad stick out, is very cool.

Children bounce back, but they are sensitive at times like this.

That is it.

Just my opinion, and anyone else's is just as valid.