hass.tibber_prices/custom_components
Julian Pawlowski 47b0a298d4 feat(periods): add midnight-crossing periods and day volatility attributes
Periods can now naturally cross midnight boundaries, and new diagnostic
attributes help users understand price classification changes at midnight.

**New Features:**

1. Midnight-Crossing Period Support (relaxation.py):
   - group_periods_by_day() assigns periods to ALL spanned days
   - Periods crossing midnight appear in both yesterday and today
   - Enables period formation across calendar day boundaries
   - Ensures min_periods checking works correctly at midnight

2. Extended Price Data Window (relaxation.py):
   - Period calculation now uses full 3-day data (yesterday+today+tomorrow)
   - Enables natural period formation without artificial midnight cutoff
   - Removed date filter that excluded yesterday's prices

3. Day Volatility Diagnostic Attributes (period_statistics.py, core.py):
   - day_volatility_%: Daily price spread as percentage (span/avg × 100)
   - day_price_min/max/span: Daily price range in minor currency (ct/øre)
   - Helps detect when midnight classification changes are economically significant
   - Uses period start day's reference prices for consistency

**Documentation:**

4. Design Principles (period-calculation-theory.md):
   - Clarified per-day evaluation principle (always was the design)
   - Added comprehensive section on midnight boundary handling
   - Documented volatility threshold separation (sensor vs period filters)
   - Explained market context for midnight price jumps (EPEX SPOT timing)

5. User Guides (period-calculation.md, automation-examples.md):
   - Added \"Midnight Price Classification Changes\" troubleshooting section
   - Provided automation examples using volatility attributes
   - Explained why Best→Peak classification can change at midnight
   - Documented level filter volatility threshold behavior

**Architecture:**

- Per-day evaluation: Each interval evaluated against its OWN day's min/max/avg
  (not period start day) ensures mathematical correctness across midnight
- Period boundaries: Periods can naturally cross midnight but may split when
  consecutive days differ significantly (intentional, mathematically correct)
- Volatility thresholds: Sensor thresholds (user-configurable) remain separate
  from period filter thresholds (fixed internal) to prevent unexpected behavior

Impact: Periods crossing midnight are now consistently visible before and
after midnight turnover. Users can understand and handle edge cases where
price classification changes at midnight on low-volatility days.
2025-11-21 23:18:46 +00:00
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tibber_prices feat(periods): add midnight-crossing periods and day volatility attributes 2025-11-21 23:18:46 +00:00