Hello,
I assume this is a custom workflow. Does this problem just apply to workflows that had already been started in 2014 and haven't finished yet? The solution could be to logically delete all of the existing workflow instances and restart them for this year. Pick one and try it for that one. Of course, test this first in a non-Prod system.
Re-executing all of the background steps won't help (or be easy to do).
Maybe you could give an example?
regards
Rick Bakker