Also copied directly from the Iowa Gas website, which states Tuesday thru Friday (which may be because of vendor set up, as mentioned above)...

Upcoming Years Event Schedule

2015

August 4th – 7th, 2015

Last edited by Speedracer; Thu Aug 13 2015 10:16 PM.
-Steve B. (WTB: 48" Flying A button, 48" black/org Phillips 66, White Star, and Chevrolet Signs. Also looking for a Wayne 866. Send a PM. Thanks.)