QDateEdit.date().toString("MMMM dd, yyyy") does not display months in English

I have a QDateEdit which is called date. No matter what I do, I'm not able to make it display the months in English, it always displays them in my current locale.

I've already tried:

self.ui.date.setLocale(QtCore.QLocale(
    QtCore.QLocale.English, QtCore.QLocale.UnitedStates))

self.ui.date.calendarWidget().setLocale(QtCore.QLocale(
    QtCore.QLocale.English, QtCore.QLocale.UnitedStates))

By doing this, the calendarWidget that pops-up when I click the widget changed to English. However, if I do:

print ui.date.date().toString("MMMM dd, yyyy")

I still get the months in Portuguese instead of English. I also tried to change the locale with python's locale module but it didn't yield any results.