Ok, let us say you have the start date in A1, type or paste the following formula in B1:
this will give you the number of months between the start data and now.
Hope this helps. Let me know if you have any questions.
The value in A1 should be a real date in order for the formula to work.
Here is a file with the formula;
Let me know if you are still having a problem
Ok, this one returns the number of years displayed in two decimals.
Hope this helps.