Hi @DiaAzul,
Thank you so much for the detailed report and simple reproducing example!
We are aware of the missing operators and have a development ticket for that already (internal reference AP-19182). We hope to address this soon, but I cannot promise a fix date unfortunately 
Sorry about that.
In your example you could convert the columns from KnimePandasExtensionArray to non-KNIME types (e.g. using pandas.to_datetime), perform the subtraction, and then store the result in the table. But I guess for your pm4py usecase that would be more difficult?
Best,
Carsten