An expression like:
DateDiff("M",[StartDate],[SomeOtherDateField]) \ 12
Will give you values
0 for the StartMonth to the end of the first year
1 for the next year
2 for the next year
You may have to do a bit of adjustment to get the exact value.
If you want the number calculated based on the month and day of the month then
things get a bit more complicated. That is if the employee started on Sept 15
and the 12 month period runs from Sept 15 to Sept 14 of the following year.
John Spencer
Access MVP 2002-2005, 2007-2010
The Hilltop Institute
University of Maryland Baltimore County