The field names are the part in [] after "as" in each of the loads, or just the name given in the source file if there is no "as". You'll see them when you build a list box, so once you've run the script, it shouldn't be confusing. They'll be these for the above example:
ID
Term Date
Term Month
Term Year
The second script I gave includes the years associated with the months. The first does not.