If it is 12 noon in chicago and you go forward 5 hours then go to the time zone of england, what time will it be then if you return back the exact way that you came? Anyone that can solve this will receive rep but of course no one on here can.
And to answer the question:
1) Chicago is GMT -6
2) When you left Chicago it was 6pm in London
3) When you arrived in London it was 11pm in London (assuming you are saying it was a 5 hour flight from Chicago to London, which is highly unrealistic by the way, to keep it real not sure what to assume since your sentence makes no f*cking sense)
4) Assuming you went around and went right back to Chicago (which is at 5PM at your time of departure in London) and it took you 5 hours then it should be 10PM in Chicago when you arrive.
I think the gist of your question is that going forward and backwards has nothing to do with the passing of time. if you go to London and fly back to Chicago 5 hours has passed each way. Again your syntax and grammar is abhorrent, so my assumption is based off a straightforward decoding of your question.