Don't know about the US, but isn't it "9to5" there too? Is there much "culture" before 9?

I can say in Germany "9to..." is also applying to cafes, supermarkets, ... pretty much nothing is open before 8 in the morning (with the exception of stuff in train stations), even some supermarkets only open at 9. So there certainly is no "culture" earlier than that. School often starts at 8, so parents frequently start the day at 6 or earlier. Same if you got an hour commuting time etc.. I don't know anybody who would wake up at 4 by choice, tho.