Even as a v e r y casual FM DXer, Cedar, I've found that ESkip and Trope can happen in broad daylight.
On a genuinely cheesy Radio Shack AM-FM ($20) one noon from here in PA, I tried for the WRTI Philly translator from Pottsville on 99.1. Yup, there was the gal doing the midday jazz show. Since the parent WRTI signal is on 90.1, I chuckled when she said 'Jazz 99'. Then I did a double-take when she gave out request line numbers for Dade and Broward counties. It was not Pottsville's jazz, but Miami's.
In the car once, about 2:30PM, not even a mile from the house, I tuned around -- analog dial -- and heard some neat oldies .... Ronettes, Cornelius Bros. 'Oldies 108' it was.
Okay.
They played an ad for some car dealership on Highway 41. Now I don't know of any Highway 41 in Pennsylvania, at least not one with businesses. Then, of course, the ad announced two locations. One in Bradenton, and one in Sarasota. The station was WSRZ 107.9 in Sarasota. Huh?!?!? THAT Highway 41? Like, omigod!
I thought I may've been the farthest listener that bright, sunny afternoon. But some DXer from Poughkeepsie NY also heard WSRZ. 'Poe - KIPP -see' is an additional 150 miles or so further than I was.
Was never a TV DXer, but there were two instances of ESkip (again, in broad daylight) that I'd be glad to submit here if anyone gives a flying one, hi. What I'm trying to say is that my largely contemptible receiving equipment heard and saw these things in the daytime sunshine. FM and TV don't seem to follow the conventional reception rules.