Cron Expression: Every 5 Minutes Between 9 AM and 5 PM (*/5 9-17 * * *)

The cron expression */5 9-17 * * * executes a task every 5 minutes during business hours (9 AM to 5 PM), making it ideal for frequent monitoring, queue processing, and tasks that need regular execution during work hours.

Expression Breakdown

*/5 9-17 * * *
│   │   │ │ │
│   │   │ │ └─── Day of week: * (every day)
│   │   │ └───── Month: * (every month)
│   │   └─────── Day of month: * (every day)
│   └─────────── Hour: 9-17 (9 AM to 5 PM)
└─────────────── Minute: */5 (every 5 minutes)

Field Values

Combined Syntax

• Step value (*/5): Every 5th minute
• Range (9-17): Hours 9 through 17
• Combined: Every 5 minutes during 9 AM to 5 PM

Execution Time

This expression runs 108 times per day (9 hours × 12 executions per hour) at:

• Every 5 minutes from 09:00 to 17:55

Common Use Cases

1. Frequent Business Monitoring

*/5 9-17 * * * /usr/local/bin/business-monitor.sh

Monitor system health, application status, or services frequently during business hours.

2. Queue Processing

*/5 9-17 * * * /usr/bin/node /app/process-queue.js

Process job queues or message queues regularly during work hours.

3. Data Synchronization

*/5 9-17 * * * /usr/bin/python3 /scripts/sync-data.py

Sync data from external systems or APIs frequently during business hours.

4. Cache Refresh

*/5 9-17 * * * /usr/bin/python3 /scripts/refresh-cache.py

Refresh cached data or computed values regularly during work hours.

Example Implementations

Business Monitor Script

#!/bin/bash
# /usr/local/bin/business-monitor.sh

LOG_FILE="/var/log/business-monitor.log"
THRESHOLD_CPU=80
THRESHOLD_MEM=85

CPU_USAGE=$(top -bn1 | grep "Cpu(s)" | awk '{print $2}' | cut -d'%' -f1)
MEM_USAGE=$(free | grep Mem | awk '{printf "%.0f", $3/$2 * 100}')

if (( $(echo "$CPU_USAGE > $THRESHOLD_CPU" | bc -l) )); then
    echo "$(date): WARNING - CPU usage at ${CPU_USAGE}%" >> $LOG_FILE
fi

if [ $MEM_USAGE -gt $THRESHOLD_MEM ]; then
    echo "$(date): WARNING - Memory usage at ${MEM_USAGE}%" >> $LOG_FILE
fi

Best Practices

1. Business Hours: Focuses execution during work hours only
2. Execution Time: Tasks should complete within 4-5 minutes
3. Error Handling: Implement comprehensive error handling and logging
4. Idempotency: Ensure tasks can run multiple times safely
5. Resource Management: Monitor CPU, memory, and I/O usage

When to Use

✅ Good for:

• Frequent monitoring during business hours
• Queue processing
• Data synchronization
• Cache refresh
• Regular business-hour checks

❌ Avoid for:

• Real-time critical operations (use every minute)
• Very long-running processes
• Tasks outside business hours

Related Patterns

Conclusion

The */5 9-17 * * * expression is perfect for frequent operations during business hours. It provides regular execution every 5 minutes during work hours while avoiding unnecessary execution outside business time, making it ideal for monitoring, queue processing, and data synchronization during peak usage periods.