The issue in this case is that the pylint is not certain that .total_seconds() exists, but of course it does. The error mentions FakeDateTime which I'm guessing is some auto-generated thing from some layer I don't know about. It does not appear to be a class defined anywhere in our source tree. There are many lint errors in the system along the lines of the one we see here, for example in the code just above here. I think I should just take out the lint-disable, so my call to .total_seconds() just looks like all the others.