Cron Expression: Every Day at 6:00 PM (0 18 * * *)

The cron expression 0 18 * * * executes a task every day at 6:00 PM (18:00), making it ideal for end-of-business-day operations, daily summaries, and tasks that should run when the workday ends.

Expression Breakdown

bash

0 18 * * *
│  │  │ │ │
│  │  │ │ └─── Day of week: * (every day)
│  │  │ └───── Month: * (every month)
│  │  └─────── Day of month: * (every day)
│  └────────── Hour: 18 (at hour 18, 6:00 PM)
└───────────── Minute: 0 (at minute 0)

Field Values

Field	Value	Meaning
Minute	`0`	At minute 0
Hour	`18`	At hour 18 (6:00 PM)
Day of Month	`*`	Every day (1-31)
Month	`*`	Every month (1-12)
Day of Week	`*`	Every day of week (0-7)

Execution Time

This expression runs once per day at:

18:00 (6:00 PM)

Common Use Cases

1. End-of-Day Reports

bash

0 18 * * * /usr/bin/python3 /scripts/generate-end-of-day-report.py

Generate and send end-of-business-day reports or summaries.

2. Daily Summaries

bash

0 18 * * * /usr/bin/python3 /scripts/create-daily-summary.py

Create daily summaries, statistics, or analytics for the business day.

3. Data Backup

bash

0 18 * * * /usr/local/bin/end-of-day-backup.sh

Create backups or snapshots at the end of the business day.

4. Cache Refresh

bash

0 18 * * * /usr/bin/python3 /scripts/refresh-cache.py

Refresh cached data or computed values for the next day.

Example Implementations

End-of-Day Report Script

python

# generate-end-of-day-report.py
import json
from datetime import datetime
import sqlite3

def generate_end_of_day_report():
    conn = sqlite3.connect('/var/data/app.db')
    cursor = conn.cursor()
    
    # Get daily metrics
    cursor.execute('''
        SELECT 
            COUNT(*) as total_requests,
            AVG(response_time) as avg_response_time,
            COUNT(CASE WHEN status_code >= 400 THEN 1 END) as errors,
            COUNT(DISTINCT user_id) as unique_users
        FROM requests
        WHERE DATE(timestamp) = DATE('now')
    ''')
    
    metrics = cursor.fetchone()
    
    report = {
        'date': datetime.now().strftime('%Y-%m-%d'),
        'time': 'end_of_day',
        'metrics': {
            'total_requests': metrics[0],
            'avg_response_time': round(metrics[1], 2) if metrics[1] else 0,
            'errors': metrics[2],
            'unique_users': metrics[3],
            'error_rate': round((metrics[2] / metrics[0] * 100), 2) if metrics[0] > 0 else 0
        }
    }
    
    # Save report
    with open(f'/var/reports/end_of_day_{datetime.now().strftime("%Y%m%d")}.json', 'w') as f:
        json.dump(report, f, indent=2)
    
    print(f"{datetime.now()}: End-of-day report generated")
    conn.close()

if __name__ == '__main__':
    generate_end_of_day_report()

Daily Summary Script

python

# create-daily-summary.py
from datetime import datetime
import sqlite3

def create_daily_summary():
    conn = sqlite3.connect('/var/data/app.db')
    cursor = conn.cursor()
    
    # Aggregate daily data
    cursor.execute('''
        INSERT INTO daily_summaries (date, total_transactions, revenue, created_at)
        SELECT 
            DATE('now'),
            COUNT(*),
            SUM(amount),
            ?
        FROM transactions
        WHERE DATE(created_at) = DATE('now')
    ''', (datetime.now(),))
    
    conn.commit()
    conn.close()
    
    print(f"{datetime.now()}: Daily summary created")

if __name__ == '__main__':
    create_daily_summary()

Best Practices

Timing: 6 PM aligns with typical business day end
Error Handling: Implement comprehensive error handling and logging
Locking: Use file locks to prevent concurrent execution
Monitoring: Set up alerts for failed jobs
Performance: Optimize tasks to complete efficiently

When to Use

✅ Good for:

End-of-day reports
Daily summaries
End-of-day backups
Cache refresh
Business day wrap-up tasks

❌ Avoid for:

Real-time critical operations
Very long-running processes

Related Patterns

Pattern	Expression	Description
Daily at noon	`0 12 * * *`	Midday
Daily at 6 PM	`0 18 * * *`	End of business day
Daily at 11 PM	`0 23 * * *`	Late evening

Conclusion

The 0 18 * * * expression is perfect for end-of-business-day operations. It's commonly used for reports, summaries, and tasks that should run when the workday ends, providing closure on daily operations and preparing for the next day.

Cron Expression: Every Day at 6:00 PM (0 18 * * *)

Need to generate a cron expression?

Cron Expression: Every Day at 6:00 PM (0 18 * * *)

Expression Breakdown

Field Values

Execution Time

Common Use Cases

1. End-of-Day Reports

2. Daily Summaries

3. Data Backup

4. Cache Refresh

Example Implementations

End-of-Day Report Script

Daily Summary Script

Best Practices

When to Use

Related Patterns

Conclusion

Need to generate a cron expression?