I've come across these sentences:
"American society today is a world of conflict, challenge, struggle, and potential."
"Traffic jams today are hardcore"
They both violate the rules of placing adverbs of definite time in a sentence. I've searched and haven't found any rule other than: You ought to put it in the front position or in the end of a sentence. Like "Today I'm going to buy ice-cream" or "I'm going to buy ice-cream today".
Is there such a rule?