You must have them set for at least three days before they can evolve.

That is all.

Just for clarification, the rule above is no longer in effect.

You must have owned a profile pokemon for three days before it can evolve.

If it can evolve again after that, you must wait an additional day (assuming you get all the posts).

Sooo, say I get a Weedle on January 18th. Even if I get 15 posts in, it can't evolve until the 21st. Then if I want to evolve it again, I need to get 20 posts and wait until at least the 22nd.

Of course, if you guys start postwhoring then we'll have to go back to the old rule