Hi
There is nothing wrong with your formula that I can see. The issue is with your data. You are comparing "Apples" with "Pears" so to speak. So when you try and compare the two dates each date has the following format so will never ever result in a TRUE result:

One date is in the format 16/04/14 00:00 and the other date you are comparing with is in the same format but with a different time setting such as 16/04/14 11:00. So you see you will never get a TRUE match.

Hope this helps.
Tony