Ahh, but these are not dates; if they were, you could have used the built-in DateDiff function to compute the difference for you.
The values you show are text strings, and you can manipulate these using the Left and Right functions to extract the year and month components accordingly, and the Val function to take the numeric value of these text substrings.
The year and the month can be recovered from the string like this:
- Val(Left([name of the field concerned], 4))
-
Val(Right([name of the field concerned], 2))
Once you've got these you can manipulate the result to find the difference between two such values. I leave it for you to work out how to do this once you've extracted the year and month components for each 'date' concerned.
-Stewart