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Cron Expression: Every Day at 11:00 PM (0 23 * * *)

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Cron Expression: Every Day at 11:00 PM (0 23 * * *)

The cron expression 0 23 * * * executes a task every day at 11:00 PM (23:00), making it ideal for late evening maintenance, final data processing, and tasks that should run before midnight.

Expression Breakdown

bash
0 23 * * *
│  │  │ │ │
│  │  │ │ └─── Day of week: * (every day)
│  │  │ └───── Month: * (every month)
│  │  └─────── Day of month: * (every day)
│  └────────── Hour: 23 (at hour 23, 11:00 PM)
└───────────── Minute: 0 (at minute 0)

Field Values

FieldValueMeaning
Minute0At minute 0
Hour23At hour 23 (11:00 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:

  • 23:00 (11:00 PM)

Common Use Cases

1. Final Data Processing

bash
0 23 * * * /usr/bin/python3 /scripts/final-data-processing.py

Process final data batches or complete daily data operations.

2. Pre-Midnight Cleanup

bash
0 23 * * * /usr/local/bin/pre-midnight-cleanup.sh

Clean up temporary files, old cache entries, or stale data before midnight.

3. Final Backups

bash
0 23 * * * /usr/local/bin/final-backup.sh

Create final backups or snapshots before the day ends.

4. System Preparation

bash
0 23 * * * /usr/local/bin/prepare-for-midnight.sh

Prepare systems, databases, or services for midnight operations.

Example Implementations

Final Data Processing Script

python
# final-data-processing.py
from datetime import datetime
import sqlite3

def final_data_processing():
    conn = sqlite3.connect('/var/data/app.db')
    cursor = conn.cursor()
    
    # Finalize daily transactions
    cursor.execute('''
        UPDATE daily_transactions
        SET finalized = 1, finalized_at = ?
        WHERE DATE(created_at) = DATE('now')
        AND finalized = 0
    ''', (datetime.now(),))
    
    # Archive completed records
    cursor.execute('''
        INSERT INTO daily_archive
        SELECT * FROM daily_transactions
        WHERE DATE(created_at) = DATE('now', '-1 day')
    ''')
    
    conn.commit()
    conn.close()
    
    print(f"{datetime.now()}: Final data processing completed")

if __name__ == '__main__':
    final_data_processing()

Pre-Midnight Cleanup Script

bash
#!/bin/bash
# /usr/local/bin/pre-midnight-cleanup.sh

TEMP_DIR="/tmp/app"
CACHE_DIR="/var/cache/app"
LOG_FILE="/var/log/cleanup.log"

# Clean temporary files older than 1 hour
find $TEMP_DIR -type f -mmin +60 -delete

# Clean old cache entries
find $CACHE_DIR -type f -mtime +1 -delete

# Clean old log files
find /var/log/app -name "*.log" -mtime +7 -exec gzip {} \;

echo "$(date): Pre-midnight cleanup completed" >> $LOG_FILE

Best Practices

  1. Timing: 11 PM ensures tasks complete before midnight jobs start
  2. Error Handling: Implement comprehensive error handling and logging
  3. Locking: Use file locks to prevent concurrent execution
  4. Monitoring: Set up alerts for failed jobs
  5. Coordination: Ensure tasks complete before midnight operations

When to Use

Good for:

  • Final data processing
  • Pre-midnight cleanup
  • Final backups
  • System preparation
  • Late evening maintenance

Avoid for:

  • Real-time critical operations
  • Very long-running processes that might overlap with midnight

Related Patterns

PatternExpressionDescription
Daily at 6 PM0 18 * * *End of business day
Daily at 11 PM0 23 * * *Late evening
Daily at midnight0 0 * * *Start of next day

Conclusion

The 0 23 * * * expression is perfect for late evening operations that should complete before midnight. It's commonly used for final data processing, cleanup tasks, and system preparation, ensuring everything is ready for midnight operations and the start of a new day.

Need to generate a cron expression?

Use CronOS to generate any cron expression you wish with natural language. Simply describe what you need, and we'll create the perfect cron expression for you. It's completely free!

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