DateTimeField Announcement.valid_from received a naive datetime

/home/nik/.cache/pypoetry/virtualenvs/aleksis-hTTXhA9V-py3.7/lib/python3.7/site-packages/django/db/models/fields/__init__.py:1368: RuntimeWarning: DateTimeField Announcement.valid_from received a naive datetime (2020-02-28 16:43:00.680868) while time zone support is active.
  RuntimeWarning)
/home/nik/.cache/pypoetry/virtualenvs/aleksis-hTTXhA9V-py3.7/lib/python3.7/site-packages/django/db/models/fields/__init__.py:1368: RuntimeWarning: DateTimeField Announcement.valid_until received a naive datetime (2020-02-28 16:43:00.680868) while time zone support is active.
  RuntimeWarning)