# Timezone Fix - Complete Implementation

## Summary

All datetime values are now stored and processed in UTC. Display timezone is configurable and only used for UI display.

## Changes Made

### 1. `utils/timezone_utils.py` - Core Timezone Utilities

**Changed:**
- All internal processing now uses UTC (not Sofia timezone)
- `now_system()` → `now_utc()` (returns UTC)
- `normalize_timestamp()` → Returns UTC (not Sofia)
- `normalize_dataframe_timestamps()` → Returns UTC
- `normalize_dataframe_index()` → Returns UTC
- Added `now_display()` for UI display timezone
- Added `to_display_timezone()` for converting UTC to display timezone
- Deprecated `to_sofia()`, `now_sofia()`, `to_system_timezone()`

**Key Functions:**
- `now_utc()` - Use for all internal processing
- `to_utc()` - Convert to UTC
- `now_display()` - Get current time in display timezone (UI only)
- `to_display_timezone()` - Convert UTC to display timezone (UI only)
- `format_timestamp_for_display()` - Format UTC timestamp for display

### 2. `core/config.py` - Configuration

**Added:**
- `display_timezone` in default config (default: 'Europe/Sofia')

### 3. `config.yaml` - Config File

**Changed:**
- `system.timezone` → `system.display_timezone`
- All internal processing uses UTC regardless of this setting

### 4. `ANNOTATE/core/inference_training_system.py`

**Fixed:**
- All `datetime.now(timezone.utc)` calls already correct
- Added comments clarifying UTC usage

### 5. `ANNOTATE/core/real_training_adapter.py`

**Fixed:**
- All `datetime.now()` → `datetime.now(timezone.utc)`
- Lines: 2498, 3057, 4258, 4456

### 6. `ANNOTATE/web/app.py`

**Fixed:**
- `datetime.now()` → `datetime.now(timezone.utc)`
- Lines: 3057, 3438

### 7. `ANNOTATE/web/static/js/chart_manager.js`

**Already Correct:**
- Uses `toISOString()` for UTC consistency
- `normalizeTimestamp()` helper ensures UTC

## Configuration

### Display Timezone

Set in `config.yaml`:
```yaml
system:
  display_timezone: "Europe/Sofia"  # Change this to your preferred display timezone
```

Or in code:
```python
from utils.timezone_utils import get_display_timezone
display_tz = get_display_timezone()  # Returns configured display timezone
```

## Usage Guidelines

### For Internal Processing (Backend)

**ALWAYS use UTC:**
```python
from datetime import datetime, timezone
from utils.timezone_utils import now_utc, to_utc

# Get current time
current_time = datetime.now(timezone.utc)  # or now_utc()

# Convert to UTC
utc_time = to_utc(some_datetime)

# Store in database
timestamp = datetime.now(timezone.utc).isoformat()
```

### For UI Display (Frontend/Backend)

**Convert UTC to display timezone only for display:**
```python
from utils.timezone_utils import to_display_timezone, format_timestamp_for_display

# Convert UTC to display timezone
display_time = to_display_timezone(utc_datetime)

# Format for display
formatted = format_timestamp_for_display(utc_datetime, '%Y-%m-%d %H:%M:%S')
```

### JavaScript (Frontend)

**Already handles UTC correctly:**
```javascript
// All timestamps should be in UTC ISO format
const timestamp = new Date(utcIsoString).toISOString();

// For display, convert to local timezone (browser handles this)
const displayTime = new Date(utcIsoString).toLocaleString();
```

## Migration Notes

### Old Code (DEPRECATED)
```python
from utils.timezone_utils import now_system, to_sofia, normalize_timestamp

# OLD - Don't use
time = now_system()  # Returns Sofia timezone
time = to_sofia(dt)  # Converts to Sofia
time = normalize_timestamp(ts)  # Returns Sofia timezone
```

### New Code (CORRECT)
```python
from datetime import datetime, timezone
from utils.timezone_utils import now_utc, to_utc, to_display_timezone

# NEW - Use this
time = datetime.now(timezone.utc)  # or now_utc()
time = to_utc(dt)  # Converts to UTC
display_time = to_display_timezone(utc_time)  # For UI only
```

## Benefits

1. **No More Timezone Misalignment**: All predictions align with candles
2. **Consistent Storage**: All database timestamps in UTC
3. **Configurable Display**: Users can set their preferred display timezone
4. **Clean Implementation**: No more timezone patches
5. **International Support**: Easy to support multiple timezones

## Testing

1. **Verify Predictions Align with Candles**
   - Start inference
   - Check that predictions appear at correct candle times
   - No 1-2 hour offset

2. **Verify Display Timezone**
   - Change `display_timezone` in config
   - Restart application
   - Verify UI shows times in configured timezone

3. **Verify UTC Storage**
   - Check database timestamps are in UTC
   - Check all API responses use UTC
   - Check logs use UTC

## Removed Code

All old timezone patches have been removed:
- No more `to_sofia()` conversions in processing
- No more `normalize_timestamp()` converting to Sofia
- No more `SYSTEM_TIMEZONE` usage in processing
- Clean, unified UTC implementation