Pay rate increase based on hours per year

We have a new union rule that requires a 5% pay rate increase once an individual has worked 48 hours of that particular pay type in the year.  The rate remains effective from the 49th hour through the end of the calendar year.  Is this kind set up possible in JDE?  I'm studying custom calculations but I'm not seeing anything that will determine when the threshold is reached.  We lost our long time HCM business analyst and I'm a technical person trying to help out.  Any general pointers in the right direction or creative solutions would be appreciated.