In a table, you don't.  Access is a database, not a spreadsheet.  Do the
calculation in a query and use the query instead of the table.

YourNewFieldName: DateAdd("m", 15, FirstFieldName)

Hi Steven,

Try this in your query:

x: DateAdd("m";15;[yourdatefield])

Where x=the name you want to give as a columnheading (replcae with your own)
Where yourdatefield has to be replaced with your own datefield.
p.s. depending on your regional settings the ; might also be a , my guess is
that you should use the comma instead of the ;

hth

Not all training is required to repeat at the same interval.  
So build a table with training courses in two fields --
Course   Interval
Develop intervals based on your lowest common denominator.  If you have
traing at one year, 18 months, and quarterly then use number of months - 12,
18, 3.
If by chance you have some at a lower interval like five weeks then you wil
need everthing in weeks.
To calculate the next training use DateDiff function.

Going further some employees may take a class but not need it as a training
require but you still want to capture the fact they attended but not schedule
them again.  Here you would want another table that has EmpID, Course, Reqd
fields to set criteria for planning.