It was Robert Ross who set off this train of thought. He said: " The AM BCB Season is starting to wind down here now, and soon I’ll be switching over to FM DXing for the Spring and Summer. "

I'm trying to assemble a set of basic assumptions about AM and FM dxing. I've come up with the following . . . please have a look and point me in the  right direction.

AM DX
Season: Fall/winter
Time: night/dawn
Frequency "holes" where it is easier to search: 1540-1700 (fewer stations)
Location: near the ocean, if you can manage it

FM DX
Season: Spring/summer?
Time: daytime?
Frequency holes: ??
Location: highest elevation??
Also: does ducting occur on the FM band? (I know it does on ham 2 meter).