The default setting for sqlalchemy.DateTime columns on postgres databases is on timezone=True, while pythons default setting for datetime stuff seems to be timezone=False, hence the two defaults ...

Python 3.11 Flask 3.0, SQLAlchemy 2.0, (psycopg2-binary 2.9.x or psycopg 3.x) Gunicorn (1 worker for demo) Docker Desktop (Linux engine) + Docker Compose v2 Postgres 16 ...