Now, while what wrote above is true, I’d still love to at least try and help here. 😀
I took a look at your events page and did not see the gray bar — I just saw the “date” box sitting there. Here’s a screenshot of exactly what I see, for reference (click for a larger-sized image):

1. Can you help clarify exactly where the gray bar shows up for you? Share a link directly to the pages on your site on which it is visible.
2. Can you clarify exactly what you’re trying to leave showing there? You said in your post here, “Here’s what I used to remove all of the search bar except the date:”, then pasted some CSS. So are you trying to keep the “date” box then, but just not any gray behind it? Or should there be nothing there—no date box, no other search box, no gray bar, nothing…?
Thanks! 😀
George