>What is DateDiff here and does it calculate with decimals or just the integer age?

DafeDiff() is a .NET method to calculate the difference in time, based on the parameter used, between two dates. You would have to try it out and enhance as needed. This has been a while since I had to touch that method. But, I would say it is only returning the actual age not taking care of the months. But, that shouldn't be too difficult to enhance.