For a given cell with a date in it, How do you distinguish between training that is required annually and training required biannually? For a given column does everyone require training with the same frequency or do some people need the training annually and other less often?
If everyone requires a particular training with the same other-than-annual frequency, create a conditional formatting rule (for example =A1>TODAY()-670) just for that column, place it in front of the annual rule, and set the Stop If True flag.