Files
NestQuest/api/host_zone.py
T
dev_agentandClaude Opus 5.5 474c84bf35 Publish the API's effective timezone and tolerate an older snapshot payload
TZ-002: with no zone stored the API reads its clock in the host's local
time, but the panel fell back to Home Assistant's zone and the admin app
to the browser's, so dates could disagree near midnight. The API now
names the zone it actually uses (api/host_zone.py: the stored zone, else
the host's own IANA zone from TZ, /etc/localtime or /etc/timezone) and
publishes it as the panel snapshot's `timezone` and the admin settings'
read-only `effective_timezone`. Both cards and the admin app format in
that one zone; Home Assistant's or the browser's zone applies only when
none is published.

TZ-003: snapshot_from_api_payload reads `timezone` with a "" default, so
an integration upgraded ahead of its API keeps refreshing against the
pre-change payload.

Task 7e173881-fb99-426f-a2f0-2678439ffc39

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-30 09:50:25 -04:00

63 lines
2.2 KiB
Python

"""The API's effective application timezone (task 7e173881).
The admin-stored ``timezone`` setting is the single source of local-time
truth; stored empty, the API reads its clock in the API host's local
time. :func:`effective_timezone` names the zone the API actually uses —
the stored zone, or else the host's own IANA zone — so the panel cards
and the admin app format local time in exactly the API's zone instead of
guessing with Home Assistant's or the browser's. ``""`` only when the
host's zone genuinely cannot be named.
"""
from __future__ import annotations
import os
from collections.abc import Mapping
from pathlib import Path
from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
def _valid_zone(name: str) -> str:
"""Return ``name`` if it is a loadable IANA zone key, else ``""``."""
name = name.strip().removeprefix(":")
if not name:
return ""
try:
ZoneInfo(name)
except (ZoneInfoNotFoundError, ValueError):
return ""
return name
def host_timezone(
environ: Mapping[str, str] = os.environ,
timezone_file: Path = Path("/etc/timezone"),
localtime: Path = Path("/etc/localtime"),
) -> str:
"""Name the API host's local zone as an IANA key, or ``""``.
In the order the C library honours them: the ``TZ`` environment
variable, then the ``/etc/localtime`` zoneinfo link (with Debian's
``/etc/timezone`` naming it when the link is a copy). A host with
none of them configured runs UTC. A setting that names no IANA
zone (a POSIX rule string, a copied file) is ``""``.
"""
configured = environ.get("TZ")
if configured is not None:
# An empty TZ is UTC to the C library.
return _valid_zone(configured) if configured.strip() else "UTC"
if localtime.is_symlink():
target = str(localtime.resolve())
marker = "/zoneinfo/"
if marker in target:
return _valid_zone(target.split(marker, 1)[1])
if timezone_file.is_file():
return _valid_zone(timezone_file.read_text(encoding="utf-8"))
if not localtime.exists():
return "UTC"
return ""
def effective_timezone(stored: str) -> str:
"""The zone the API reads its clock in: ``stored``, else the host's."""
return stored or host_timezone()