Add a datetime module with a UNIX_EPOCH constant

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/core/datetime.py

@@ -0,0 +1,9 @@
+# License: MIT
+# Copyright © 2024 Frequenz Energy-as-a-Service GmbH
+
+"""Timeseries basic types."""
+
+from datetime import datetime, timezone
+
+UNIX_EPOCH = datetime.fromtimestamp(0.0, tz=timezone.utc)
+"""The UNIX epoch (in UTC)."""