When the creep said "tonight" he probably shielded himself from any claim of deadly threat so you would have been in a touchy situation legally if you had used deadly force, etc. "Tonight" hasn't happened yet so there was no threat. Street crazies, communist rioters, and others know how to manipulate the legal system to set people up. Thanks for the heads up, if anybody asks me if I want to die "tonight" I will tell him "Sure, as long as I can take somebody down with me--tonight".
None-the-less, the comment was enough to get you off condition white and think about your alternatives. As somebody said, making some distance and just saying "back off" like you meant it would probably have worked as well as anything else.
If you are not familiar with condition white, google Col. Cooper.
Sometimes you go with your gut. Once I was with my wife and step-daughter in a so-so urban area just after dark. The street we had just turned off of was full of normal people. Unbeknownst to me, the city had just cleaned up a park a block away, thus chasing all the street crazies 1 block downhill. This is probably why the ice cream parlor that used to light up the street was no longer open. Anyway, a long-haired creepy looking fellow carrying what looked like a wedding flower arrangement in a cardboard box crossed the street saying he wanted to show me his "baby" motioning to the box. Well, I had no desire to see what was in that box nor to let him close the distance to us so I stepped forward into the street, raised my fist, and told him I was going to break his *****head. Mission accomplished, he got a terrified look on his face, ran down the block into a store and was not seen again. Sorry, maybe not to the letter of the law, but me and my family got out OK. And, of course, I found another street to walk down at night since this one had gone bad.