-adding one of C<$self>'s terms fields. Note that the resulting date
-will be the following Monday if the result falls on a weekend.
+adding one of C<$self>'s terms fields if automatic calculation is on;
+otherwise returns the currently-set due date (which must be provided)
+or the reference date, whichever is later.
+
+Note that for automatic calculation the resulting date will be the
+following Monday if the result falls on a weekend.