This document explains how to handle datetime.UTC compatibility between Python 3.10 and Python 3.11+.

Python 3.11 introduced datetime.UTC as a convenient constant for the UTC timezone. However, this constant is not available in Python 3.10 and earlier versions, causing ImportError when trying to import it:

# This fails on Python 3.10:
from datetime import datetime, UTC

The recommended approach is to import UTC from the retrorecon.datetime_utils module:

from retrorecon.datetime_utils import UTC, utc_now, utc_datetime

# Use UTC timezone
now = utc_now()
dt = utc_datetime(2023, 1, 1, 12, 0, 0)

If you need to implement this pattern in your own code:

# Python 3.10 compatibility pattern
try:
    from datetime import datetime, UTC
except ImportError:
    from datetime import datetime, timezone
    UTC = timezone.utc

# Now UTC works on both Python 3.10 and 3.11+
now = datetime.now(UTC)

Also replace deprecated datetime functions:

# Old (deprecated):
dt = datetime.utcfromtimestamp(timestamp)

# New (recommended):
from retrorecon.datetime_utils import UTC
dt = datetime.fromtimestamp(timestamp, UTC)

Run the compatibility tests to verify everything works:

python -m pytest tests/test_datetime_utc_compatibility.py
python -m pytest tests/test_datetime_utils.py
python test_python310_compatibility.py

• retrorecon/datetime_utils.py - New compatibility module
• layerslayer/client.py - Fixed deprecated utcfromtimestamp usage
• tests/test_datetime_utc_compatibility.py - Compatibility tests
• tests/test_datetime_utils.py - Module tests
• test_python310_compatibility.py - Demonstration script