CSV upload fails in inventory optimization migration due to date format mismatch between source and target

Migrating inventory optimization data to Blue Yonder Luminate 2023.1 via CSV upload and encountering persistent date format rejections. Our legacy system exports dates as MM/DD/YYYY but Luminate expects YYYY-MM-DD ISO format. The upload validation fails with:


Error: Invalid date format in row 1847, column 'last_stock_date'
Expected: YYYY-MM-DD, Received: 04/15/2024

We have 340,000 inventory records across 8 warehouses to migrate. Manual CSV preprocessing isn’t feasible at this scale. I tried Excel find/replace but it corrupts leading zeros and breaks product codes. Has anyone automated date normalization for large-scale CSV uploads? What’s the best ETL scripting approach?

Consider building a reusable ETL pipeline rather than one-off scripts. We created a preprocessing framework that handles date normalization, encoding fixes, delimiter standardization, and validation checks. It processes our inventory CSVs automatically before upload and has saved us countless hours on recurring migrations.

Here’s a quick Python approach:

import pandas as pd
df = pd.read_csv('inventory.csv')
df['last_stock_date'] = pd.to_datetime(df['last_stock_date']).dt.strftime('%Y-%m-%d')
df.to_csv('inventory_normalized.csv', index=False)

This handles the date normalization cleanly. But you also need CSV preprocessing for other potential issues - null values, encoding problems, delimiter inconsistencies. Build a complete validation pipeline.

Here’s a comprehensive solution covering all three focus areas:

Date Normalization: Implement intelligent date parsing that handles multiple formats automatically:

import pandas as pd
from dateutil import parser

def normalize_date(date_str):
    if pd.isna(date_str) or date_str == '':
        return ''
    try:
        # Try parsing with automatic format detection
        parsed = parser.parse(str(date_str), dayfirst=False)
        return parsed.strftime('%Y-%m-%d')
    except:
        return 'INVALID_DATE'

df['last_stock_date'] = df['last_stock_date'].apply(normalize_date)

For warehouses with mixed regional formats (DD/MM/YYYY vs MM/DD/YYYY), create a warehouse mapping table that specifies the date format for each location. Apply the appropriate parsing strategy based on source warehouse.

CSV Preprocessing: Build a complete preprocessing pipeline that addresses all data quality issues before upload:

import pandas as pd
import logging

# Configure logging for audit trail
logging.basicConfig(filename='migration_audit.log', level=logging.INFO)

def preprocess_inventory_csv(input_file, output_file, warehouse_config):
    # Read CSV with proper encoding
    df = pd.read_csv(input_file, encoding='utf-8-sig', low_memory=False)

    logging.info(f"Processing {len(df)} records from {input_file}")

    # Normalize date columns
    date_cols = ['last_stock_date', 'next_reorder_date', 'last_audit_date']
    for col in date_cols:
        if col in df.columns:
            df[col] = df[col].apply(lambda x: normalize_date(x, warehouse_config))
            null_count = df[col].isna().sum()
            logging.info(f"{col}: {null_count} null values preserved")

    # Validate data ranges
    invalid_dates = df[df['last_stock_date'] == 'INVALID_DATE']
    if len(invalid_dates) > 0:
        logging.warning(f"Found {len(invalid_dates)} invalid dates")
        df.to_csv('invalid_dates.csv', index=False)  # Export for review

    # Remove invalid records
    df = df[df['last_stock_date'] != 'INVALID_DATE']

    # Write normalized CSV
    df.to_csv(output_file, index=False, encoding='utf-8')
    logging.info(f"Wrote {len(df)} validated records to {output_file}")

    return len(df)

This handles encoding issues, preserves nulls correctly, validates date ranges, and logs all transformations for audit purposes.

ETL Scripting: Create a production-grade ETL script that processes all 8 warehouses systematically:

warehouse_configs = {
    'WH-NA-01': {'date_format': 'MM/DD/YYYY', 'timezone': 'America/New_York'},
    'WH-EU-01': {'date_format': 'DD/MM/YYYY', 'timezone': 'Europe/London'},
    # ... configure all 8 warehouses
}

for warehouse_id, config in warehouse_configs.items():
    input_file = f"exports/{warehouse_id}_inventory.csv"
    output_file = f"normalized/{warehouse_id}_inventory_normalized.csv"

    record_count = preprocess_inventory_csv(input_file, output_file, config)
    print(f"Processed {warehouse_id}: {record_count} records ready for upload")

Add error handling, progress tracking, and validation reports. For your 340,000 records, this approach processes everything in under 2 minutes on standard hardware.

Key recommendations:

  1. Always preserve nulls as empty strings - never use default dates
  2. Log every transformation to an audit file for traceability
  3. Export invalid records to a separate CSV for manual review
  4. Validate date ranges (reject future dates, dates before 2000, etc.)
  5. Test on a small subset (1000 records) before processing the full dataset
  6. Keep original CSV files as backup until migration is confirmed successful

This solution handles mixed date formats, preserves data integrity, and provides full audit trail for compliance. Run it once per warehouse and you’ll have clean, validated CSVs ready for Luminate upload.

Add data quality checks before normalization. Count records with null dates, identify format patterns by warehouse, validate date ranges (reject future dates or dates before company founding). Log all transformations to an audit file so you can trace back any issues post-migration. This is critical for inventory data where historical accuracy matters.

Never use default dates - that creates false data. Leave nulls as empty strings in CSV. For mixed date formats, you need format detection logic. Parse with dayfirst parameter based on source warehouse region, or implement a try-except block that attempts multiple formats until one succeeds.