Reversed sunset rays

These rays were taken as I was leaving work this evening.  The unusual thing about these are they were in the eastern sky, as the sun was setting in the west!
I've never seen rays like this, on the opposite location from the sunset.  Really awesome to see, but I wish I knew what they are called. I almost thought is was an aurora borealis , but not sure!
Whatever it is, I like it! :)