PySide 6.5.0 introduced new signature for method QDateTime.fromSecsSinceEpoch(qint64 secs, const QTimeZone &timeZone) that uses QTimeZone instead of spec now.

It is assumed that QTimeZone may be intialized with help of QTimeZone::Initialization but it appears that these values are not available in python:

>>> from PySide6.QtCore import QTimeZone
>>> print(QTimeZone.UTC)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: type object 'PySide6.QtCore.QTimeZone' has no attribute 'UTC'. Did you mean: 'utc'?