Cron Expression: Every Day at Noon (0 12 * * *)

The cron expression 0 12 * * * executes a task every day at noon (12:00 PM), making it ideal for midday reports, data updates, and tasks that should run during the middle of the business day.

Expression Breakdown

bash

0 12 * * *
│  │  │ │ │
│  │  │ │ └─── Day of week: * (every day)
│  │  │ └───── Month: * (every month)
│  │  └─────── Day of month: * (every day)
│  └────────── Hour: 12 (at hour 12, noon)
└───────────── Minute: 0 (at minute 0)

Field Values

Field	Value	Meaning
Minute	`0`	At minute 0
Hour	`12`	At hour 12 (12:00 PM, noon)
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:

12:00 (noon, 12:00 PM)

Common Use Cases

1. Midday Reports

bash

0 12 * * * /usr/bin/python3 /scripts/generate-midday-report.py

Generate and send midday reports or status updates.

2. Data Refresh

bash

0 12 * * * /usr/bin/python3 /scripts/refresh-data.py

Refresh data, statistics, or computed values at midday.

3. Cache Update

bash

0 12 * * * /usr/bin/python3 /scripts/update-cache.py

Update cached data or pre-computed values.

4. Health Checks

bash

0 12 * * * /usr/local/bin/midday-health-check.sh

Run system health checks or service availability tests.

Example Implementations

Midday Report Script

python

# generate-midday-report.py
import json
from datetime import datetime
import sqlite3

def generate_midday_report():
    conn = sqlite3.connect('/var/data/app.db')
    cursor = conn.cursor()
    
    # Get morning 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
        FROM requests
        WHERE DATE(timestamp) = DATE('now')
        AND HOUR(timestamp) < 12
    ''')
    
    metrics = cursor.fetchone()
    
    report = {
        'date': datetime.now().strftime('%Y-%m-%d'),
        'time': 'midday',
        'morning_metrics': {
            'total_requests': metrics[0],
            'avg_response_time': round(metrics[1], 2) if metrics[1] else 0,
            'errors': metrics[2]
        }
    }
    
    # Save report
    with open(f'/var/reports/midday_{datetime.now().strftime("%Y%m%d")}.json', 'w') as f:
        json.dump(report, f, indent=2)
    
    print(f"{datetime.now()}: Midday report generated")
    conn.close()

if __name__ == '__main__':
    generate_midday_report()

Data Refresh Script

python

# refresh-data.py
import requests
from datetime import datetime
import sqlite3

def refresh_data():
    try:
        response = requests.get(
            'https://api.example.com/refresh',
            timeout=300
        )
        response.raise_for_status()
        
        # Update local data
        conn = sqlite3.connect('/var/data/app.db')
        cursor = conn.cursor()
        
        cursor.execute('''
            UPDATE daily_stats 
            SET last_refreshed = ?
            WHERE date = DATE('now')
        ''', (datetime.now(),))
        
        conn.commit()
        conn.close()
        
        print(f"{datetime.now()}: Data refreshed successfully")
    except Exception as e:
        print(f"{datetime.now()}: Data refresh failed: {e}")

if __name__ == '__main__':
    refresh_data()

Best Practices

Timing: Noon is a good midpoint for daily operations
Error Handling: Implement comprehensive error handling and logging
Locking: Use file locks to prevent concurrent execution
Monitoring: Set up alerts for failed jobs
Performance: Keep tasks efficient during business hours

When to Use

✅ Good for:

Midday reports
Data refresh
Cache updates
Health checks
Status updates

❌ Avoid for:

Real-time critical operations
Very long-running processes during business hours

Related Patterns

Pattern	Expression	Description
Daily at 8 AM	`0 8 * * *`	Start of business day
Daily at noon	`0 12 * * *`	Midday
Daily at 6 PM	`0 18 * * *`	End of business day

Conclusion

The 0 12 * * * expression is perfect for midday operations. It's commonly used for reports, data refresh, and status updates that should run during the middle of the business day, providing a midpoint check on daily operations.

Cron Expression: Every Day at Noon (0 12 * * *)

Need to generate a cron expression?

Cron Expression: Every Day at Noon (0 12 * * *)

Expression Breakdown

Field Values

Execution Time

Common Use Cases

1. Midday Reports

2. Data Refresh

3. Cache Update

4. Health Checks

Example Implementations

Midday Report Script

Data Refresh Script

Best Practices

When to Use

Related Patterns

Conclusion

Need to generate a cron expression?