I found 4 methods in pendulum.datetime that return a new pendulum.datetime object. The pendulum.datetime class is hardcoded in these, which could cause some inconstistencies when subclassing:

import pendulum

class MyDateTime(pendulum.DateTime):
    pass

MyDateTime.now()

The output is an instance of pendulum.DateTime while I would expect it to be an instance of MyDateTime.

This makes extending the library a bit of a hassle.