v0.18.2 - Fix Local Timezone Display in check_event_rate.py (2026-03-05)¶

What Changed?¶

This release fixes check_event_rate.py to correctly display plot timestamps in the local timezone. mdates.DateFormatter defaults to UTC regardless of the index timezone; passing tz=get_timezone() ensures X-axis labels reflect the local time. The script also now uses get_timezone() for index conversion instead of hardcoded UTC.

What's New¶

Bug Fix: Local timezone in `check_event_rate.py` plot¶

What it does: X-axis timestamps in the event rate plot now show local time (e.g. JST 18:46) instead of UTC (09:46). Both the DatetimeIndex and the axis formatter use get_timezone() consistently.

How to use it:

# Uses system timezone (default)
uv run check_event_rate.py ./data --pattern "run*.parquet" --resample 60min --save

# Override timezone via environment variable
KAZUNOKO_TZ=Europe/Paris uv run check_event_rate.py ./data --save

Installation¶

Quick Start¶

# Get the release
git checkout 0.18.2

# Setup
uv sync

# Run CLI
uv run kazunoko --help

What's Different from the Last Version?¶

🐛 Fixed¶

check_event_rate.py: mdates.DateFormatter now receives tz=get_timezone() so X-axis labels display local time instead of UTC

🔧 Changed¶

check_event_rate.py: prepare_index() converts timestamps to local timezone via get_timezone() instead of keeping UTC
check_event_rate.py: X-axis label updated to Time (<timezone>) (e.g. Time (Asia/Tokyo))
check_event_rate.py: documented KAZUNOKO_TZ environment variable in module docstring

Is It Safe to Upgrade?¶

Backward Compatible: Yes

Plot output changes: timestamps now show local time instead of UTC
No CLI option changes

Tests Passed¶

✅ Builds without errors
✅ uvx ruff check src/ passes
✅ Pre-commit hooks pass
✅ Plot verified with run163 data (18:46 JST start confirmed)

Release Details¶

Date: 2026-03-05
Version: v0.18.2
Files Changed: 1
Commits: 9a30019, 2eb5a65

Next Steps¶

Consider exposing KAZUNOKO_TZ in the CLI as a global option