0 8 1 * *
│ │ │ │ │
│ │ │ │ └─── Day of week: * (every day)
│ │ │ └───── Month: * (every month)
│ │ └─────── Day of month: 1 (first day)
│ └───────── Hour: 8 (at hour 8, 8:00 AM)
└─────────── Minute: 0 (at minute 0)

0 8 1 * * /usr/bin/python3 /scripts/generate-monthly-report.py

0 8 1 * * /usr/bin/python3 /scripts/process-monthly-billing.py

0 8 1 * * /usr/bin/python3 /scripts/sync-monthly-data.py

0 8 1 * * /usr/bin/node /app/send-monthly-digest.js

# generate-monthly-report.py
import json
from datetime import datetime, timedelta
import sqlite3

def generate_monthly_report():
    conn = sqlite3.connect('/var/data/app.db')
    cursor = conn.cursor()
    
    # Get data from last month
    today = datetime.now()
    first_day_last_month = (today.replace(day=1) - timedelta(days=1)).replace(day=1)
    last_day_last_month = today.replace(day=1) - timedelta(days=1)
    
    cursor.execute('''
        SELECT 
            COUNT(*) as total_transactions,
            SUM(amount) as total_revenue,
            COUNT(DISTINCT user_id) as unique_customers,
            AVG(amount) as avg_transaction_value
        FROM transactions
        WHERE created_at >= ? AND created_at < ?
    ''', (first_day_last_month, today.replace(day=1)))
    
    metrics = cursor.fetchone()
    
    report = {
        'month': first_day_last_month.strftime('%Y-%m'),
        'generated_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
        'metrics': {
            'total_transactions': metrics[0],
            'total_revenue': round(metrics[1], 2) if metrics[1] else 0,
            'unique_customers': metrics[2],
            'avg_transaction_value': round(metrics[3], 2) if metrics[3] else 0
        }
    }
    
    with open(f'/var/reports/monthly_{first_day_last_month.strftime("%Y%m")}.json', 'w') as f:
        json.dump(report, f, indent=2)
    
    print(f"{datetime.now()}: Monthly business report generated")
    conn.close()

if __name__ == '__main__':
    generate_monthly_report()