The documentation for equality says:

For time-valued quantities, note that calendar durations and definite quantity durations above seconds are considered unequal:

However, the documentation for comparison says:

For time-valued quantities, calendar durations and definite quantity durations above seconds are considered un-comparable:

This is inconsistent, in that equality as an operation is a comparison. The result of equality comparison of calendar and definite quantity durations should both be empty.