Oh, while we are at it, do you get royalties every time the fleet is resupplied, and do you get them if you don't have gold?
You get royalties at midnight server time from a royalty pool that fills up on your account. You get royalties from this pool depending on your commander level, the higher the commander you have, the faster you empty your royalty pool. Anyone can get royalties, provided they have an original fleet design in their account.
Here is the topic when it was introduced:
http://forum.spaceo.net/index.php/topic,2089.0.html