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Cron Expression: Every 6 Months (Jan and Jul 1st) (0 0 1 1,7 *)

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Cron Expression: Every 6 Months (Jan and Jul 1st) (0 0 1 1,7 *)

The cron expression 0 0 1 1,7 * executes a task every 6 months on January 1st and July 1st at midnight (00:00), making it ideal for semi-annual operations, reports, and maintenance tasks.

Expression Breakdown

bash
0 0 1 1,7 *
│ │ │ │  │
│ │ │ │  └─── Day of week: * (every day)
│ │ │ └───── Month: 1,7 (January and July)
│ │ └─────── Day of month: 1 (first day)
│ └───────── Hour: 0 (at hour 0, midnight)
└─────────── Minute: 0 (at minute 0)

Field Values

FieldValueMeaning
Minute0At minute 0
Hour0At hour 0 (midnight)
Day of Month1First day
Month1,7January and July
Day of Week*Every day of week (0-7)

List Syntax

The 1,7 in the month field is a list that means "January and July":

  • Runs on: January 1st and July 1st at midnight
  • These are 6 months apart

Execution Time

This expression runs 2 times per year at:

  • January 1st 00:00, July 1st 00:00

Common Use Cases

1. Semi-Annual Reports

bash
0 0 1 1,7 * /usr/bin/python3 /scripts/generate-semi-annual-report.py

Generate semi-annual reports or summaries.

2. Semi-Annual Backups

bash
0 0 1 1,7 * /usr/local/bin/semi-annual-backup.sh

Create full semi-annual backups or archives.

3. Semi-Annual Maintenance

bash
0 0 1 1,7 * /usr/local/bin/semi-annual-maintenance.sh

Run semi-annual system maintenance, cleanup, or optimization.

4. License Renewal

bash
0 0 1 1,7 * /usr/bin/python3 /scripts/process-license-renewals.py

Process semi-annual license renewals or subscriptions.

Example Implementations

Semi-Annual Report Script

python
# generate-semi-annual-report.py
import json
from datetime import datetime, timedelta
import sqlite3

def generate_semi_annual_report():
    conn = sqlite3.connect('/var/data/app.db')
    cursor = conn.cursor()
    
    today = datetime.now()
    current_month = today.month
    
    # Determine which half of year
    if current_month == 1:
        # Processing second half of previous year
        period_start = datetime(today.year - 1, 7, 1)
        period_end = datetime(today.year - 1, 12, 31)
        period = "H2"
        year = today.year - 1
    else:  # current_month == 7
        # Processing first half of current year
        period_start = datetime(today.year, 1, 1)
        period_end = datetime(today.year, 6, 30)
        period = "H1"
        year = today.year
    
    cursor.execute('''
        SELECT 
            COUNT(*) as total_transactions,
            SUM(amount) as total_revenue,
            COUNT(DISTINCT user_id) as unique_customers
        FROM transactions
        WHERE created_at >= ? AND created_at <= ?
    ''', (period_start, period_end))
    
    metrics = cursor.fetchone()
    
    report = {
        'period': period,
        'year': year,
        'period_start': period_start.strftime('%Y-%m-%d'),
        'period_end': period_end.strftime('%Y-%m-%d'),
        'metrics': {
            'total_transactions': metrics[0],
            'total_revenue': round(metrics[1], 2) if metrics[1] else 0,
            'unique_customers': metrics[2]
        }
    }
    
    with open(f'/var/reports/semi_annual_{year}_{period}.json', 'w') as f:
        json.dump(report, f, indent=2)
    
    print(f"{datetime.now()}: Semi-annual report generated for {year} {period}")
    conn.close()

if __name__ == '__main__':
    generate_semi_annual_report()

Best Practices

  1. Semi-Annual Timing: January and July provide clean 6-month boundaries
  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 semi-annual jobs
  5. Resource Management: Semi-annual jobs may be heavy, monitor resources

When to Use

Good for:

  • Semi-annual reports
  • Semi-annual backups
  • Semi-annual maintenance
  • License renewals
  • Bi-annual operations

Avoid for:

  • Tasks requiring more frequent execution
  • Real-time critical operations

Related Patterns

PatternExpressionDescription
Every 6 months0 0 1 1,7 *January and July
Quarterly0 0 1 1,4,7,10 *First day of each quarter
Yearly0 0 1 1 *January 1st only

Conclusion

The 0 0 1 1,7 * expression is perfect for semi-annual operations. It's commonly used for semi-annual reports, backups, and maintenance tasks, providing a clean 6-month cycle for recurring operations that don't need quarterly frequency.

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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