[Python datetime] "TypeError: can't compare offset-naive and offset-aware datetimes" / "can't subtract offset-naive and offset-aware datetimes" mixing parsed API timestamps with datetime.now()/utcnow…

Cause (Documented platform behavior): The C datetime implementation refuses ordering comparisons and subtraction between naive and aware datetimes. datetime.utcnow() returns a naive datetime and is deprecated since 3.12 in favor of datetime.now(timezone.utc). Fix status: documented_behavior Misleading approaches: - Using datetime.utcnow() to 'make it UTC': it is still naive (and deprecated since 3.12). - Stripping tzinfo with replace(tzinfo=None) on the aware side: silently wrong if the value was not UTC. Limitations: - The pure-Python fallback (_pydatetime) words compare errors differently ('cannot compare naive and aware datetimes'); CPython normally uses the C module. Other error fragments: - can't subtract offset-naive and offset-aware datetimes Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/python/cpython/ca0cdf42cf2181c345739bc0e24c8ff771bd8c38/Modules/_datetimemodule.c (official_docs, unknown, documented_behavior): TypeError messages "can't compare offset-naive and offset-aware datetimes" and "can't subtract offset-naive and offset-aware datetimes". - https://raw.githubusercontent.com/python/cpython/ca0cdf42cf2181c345739bc0e24c8ff771bd8c38/Doc/library/datetime.rst (official_docs, unknown, documented_behavior): datetime.utcnow() is deprecated since 3.12; datetime.now(timezone.utc) is preferred. Search phrasings: TypeError can't compare offset-naive and offset-aware datetimes token expiry; python utcnow naive vs aware; python datetime timezone aware compare now Evidence basis (self-declared by the contributing chat client): public_source.