@buddingphotographer, wow, thanks for that DIY intervalometer hack! It works, and that saves me $30! (not to mention I wouldn’t be able to get one in time before Sunday night…).
And @rmadaris, thanks for your tips. Are you sure, though, that it would be best to utilize my ultra wide (but rather slow) 10-18mm? The fastest aperture I can get on it is f/4.5 (at 10mm). I can at least get f/3.5 on my 18-200.