product_lot_sequence_per_product/DATE_FORMAT_GUIDE.md

Date Format Codes Guide

Overview

The module supports dynamic date format codes in lot/serial number sequences. These codes are automatically replaced with current date/time values when generating lot numbers.

Available Format Codes

Code	Description	Example Output	Notes
%(year)s	Full year (4 digits)	2024	Current year
%(y)s	Short year (2 digits)	24	Last 2 digits of year
%(month)s	Month (2 digits)	11	01-12, zero-padded
%(day)s	Day of month (2 digits)	20	01-31, zero-padded
%(doy)s	Day of year (3 digits)	325	001-366, zero-padded
%(woy)s	Week of year (2 digits)	47	00-53, zero-padded
%(weekday)s	Day of week	4	0=Sunday, 6=Saturday
%(h24)s	Hour (24-hour format)	14	00-23, zero-padded
%(h12)s	Hour (12-hour format)	02	01-12, zero-padded
%(min)s	Minute	30	00-59, zero-padded
%(sec)s	Second	45	00-59, zero-padded

Common Usage Examples

Example 1: Year-Month-Day Format

Configuration: %(y)s%(month)s%(day)s

Generated Lot Numbers:

• On 2024-11-20: 2411200000001, 2411200000002, ...
• On 2024-12-01: 2412010000001, 2412010000002, ...

Use Case: Daily batch tracking with compact format

Example 2: Full Date with Separators

Configuration: LOT-%(year)s-%(month)s-%(day)s-

Generated Lot Numbers:

• LOT-2024-11-20-0000001
• LOT-2024-11-20-0000002
• ...

Use Case: Human-readable lot numbers with full date

Example 3: Year and Week

Configuration: WK%(y)s%(woy)s-

Generated Lot Numbers:

• Week 47 of 2024: WK2447-0000001, WK2447-0000002, ...

Use Case: Weekly production batches

Example 4: Month and Day Only

Configuration: BATCH-%(month)s%(day)s-

Generated Lot Numbers:

• On Nov 20: BATCH-1120-0000001, BATCH-1120-0000002, ...

Use Case: Daily batches within same year

Example 5: Day of Year

Configuration: %(year)s-%(doy)s-

Generated Lot Numbers:

• Day 325 of 2024: 2024-325-0000001, 2024-325-0000002, ...

Use Case: Sequential day tracking

Example 6: Timestamp Format

Configuration: SN-%(y)s%(month)s%(day)s%(h24)s-

Generated Lot Numbers:

• At 14:30 on Nov 20, 2024: SN-24112014-0000001, SN-24112014-0000002, ...

Use Case: Hour-based batch tracking

Configuration Steps

Method 1: Via Product Form (Recommended)

1. Go to Inventory > Products
2. Open a product
3. Go to Inventory tab
4. In Custom Lot/Serial field, enter your format (e.g., %(y)s%(month)s%(day)s)
5. The system automatically creates a sequence
6. Check Next Number field to preview the format

Method 2: Via Sequence Configuration

1. Go to Settings > Technical > Sequences & Identifiers > Sequences
2. Find or create a sequence with code stock.lot.serial
3. Set Prefix to your format (e.g., LOT-%(year)s-%(month)s-%(day)s-)
4. Set Padding (e.g., 7 for 7-digit numbers)
5. Assign this sequence to your product's lot_sequence_id field

How It Works

Date Interpolation Process

1. User configures: %(y)s%(month)s%(day)s
                    ↓
2. System reads current date: 2024-11-20
                    ↓
3. Interpolation:
   %(y)s      → 24
   %(month)s  → 11
   %(day)s    → 20
                    ↓
4. Result prefix: 241120
                    ↓
5. Add sequence number: 241120 + 0000001
                    ↓
6. Final lot number: 2411200000001

Batch Generation

When generating multiple lots (e.g., 500 units):

• Date codes are interpolated once at the start
• All lots in the batch use the same date values
• Ensures consistency within a batch
• Extremely fast (single interpolation for all lots)

Best Practices

1. Choose Appropriate Granularity

Daily Batches: Use %(y)s%(month)s%(day)s

• New sequence each day
• Good for daily production runs

Monthly Batches: Use %(year)s-%(month)s-

• New sequence each month
• Good for monthly inventory cycles

Yearly Batches: Use %(year)s-

• New sequence each year
• Good for annual product lines

2. Consider Sequence Exhaustion

Problem: If you use daily format and generate 10,000 lots per day, you might exhaust the sequence.

Solution: Use appropriate padding

%(y)s%(month)s%(day)s with padding=7
→ 2411200000001 to 2411209999999 (10 million lots per day)

3. Human Readability vs Compactness

Compact (machine-friendly):

%(y)s%(month)s%(day)s → 2411200000001

Readable (human-friendly):

LOT-%(year)s-%(month)s-%(day)s- → LOT-2024-11-20-0000001

4. Avoid Time-Based Codes for Large Batches

Not Recommended:

%(y)s%(month)s%(day)s%(h24)s%(min)s

Why: If batch generation takes > 1 minute, lots might have different timestamps, causing confusion.

Better: Use date-only codes for consistency within batches.

Testing Date Formats

Quick Test

1. Configure format on product
2. Check Next Number field
3. Create a single lot manually
4. Verify the format is correct

Batch Test

# Create test product
product = env['product.product'].create({
    'name': 'Test Product',
    'tracking': 'serial',
})

# Set date format
product.product_tmpl_id.serial_prefix_format = '%(y)s%(month)s%(day)s'

# Generate 10 lots
picking = env['stock.picking'].create({...})
move = env['stock.move'].create({
    'product_id': product.id,
    'product_uom_qty': 10,
    ...
})

# Check generated lot names
# All should start with current date (e.g., 241120)

Run Test Suite

# Test date format functionality
odoo-bin -c odoo.conf -d test_db --test-tags product_lot_sequence_per_product.test_date_format

Troubleshooting

Issue: Date codes not being replaced

Symptoms: Lot names show literal %(y)s instead of 24

Causes:

1. Using old version of module (< 1.1.1)
2. Incorrect format syntax

Solutions:

1. Upgrade to version 1.1.1 or later
2. Check format syntax (must be exactly %(code)s)
3. Restart Odoo after upgrade

Issue: Wrong date values

Symptoms: Date shows yesterday or tomorrow

Causes:

1. Server timezone misconfiguration
2. Database timezone issues

Solutions:

1. Check server timezone: date command
2. Check Odoo timezone configuration
3. Verify PostgreSQL timezone settings

Issue: Inconsistent dates in batch

Symptoms: Some lots have different dates in same batch

Causes:

1. Batch generation crossed midnight
2. Using time-based codes (hour/minute)

Solutions:

1. Generate batches earlier in the day
2. Use date-only codes (avoid hour/minute)
3. Accept minor inconsistency for midnight batches

Performance Impact

Date Interpolation Performance

Single Lot:

• Date interpolation: ~0.001 seconds
• Negligible impact

Batch of 1000 Lots:

• Date interpolation: ~0.001 seconds (once)
• Sequence allocation: ~0.5 seconds
• Lot creation: ~5 seconds
• Total: ~5.5 seconds

Conclusion: Date format codes have no measurable performance impact on batch generation.

Advanced Examples

Example: Product Code + Date

PROD-A-%(year)s%(month)s-
→ PROD-A-202411-0000001

Example: Facility + Date

NYC-%(y)s%(doy)s-
→ NYC-24325-0000001 (Day 325 of 2024)

Example: Shift-Based

SHIFT-%(y)s%(month)s%(day)s-%(h24)s-
→ SHIFT-241120-14-0000001 (2 PM shift)

Example: Week-Based Production

WK%(woy)s-%(year)s-
→ WK47-2024-0000001

Migration from Fixed Prefixes

Before (Fixed Prefix)

Prefix: LOT-2024-
Generated: LOT-2024-0000001, LOT-2024-0000002, ...
Problem: Need to manually update prefix each year

After (Dynamic Date)

Prefix: LOT-%(year)s-
Generated: LOT-2024-0000001, LOT-2024-0000002, ...
Benefit: Automatically updates to LOT-2025- next year

Migration Steps

1. Note current sequence number
2. Update prefix to use date codes
3. Verify next number is correct
4. Test with single lot
5. Deploy to production

Summary

Date format codes provide:

• ✓ Dynamic lot numbering based on current date/time
• ✓ Automatic date updates (no manual changes needed)
• ✓ Flexible formatting options
• ✓ No performance impact
• ✓ Batch generation support
• ✓ Full compatibility with all module features

Use date format codes to create intelligent, self-updating lot numbering schemes that adapt to your production schedule automatically.