Cron Expression: Every Minute During First 5 Days of Month (* * 1-5 * *)

The cron expression * * 1-5 * * executes a task every minute during the first 5 days of every month, making it ideal for intensive start-of-month operations, monitoring, or tasks that need frequent execution at the beginning of each month.

Expression Breakdown

* * 1-5 * *
│ │ │  │ │
│ │ │  │ └─── Day of week: * (every day)
│ │ │  └───── Month: * (every month)
│ │ └──────── Day of month: 1-5 (first 5 days)
│ └────────── Hour: * (every hour)
└──────────── Minute: * (every minute)

Field Values

Range Syntax

The 1-5 in the day of month field is a range that means "days 1 through 5":

• Runs every minute on: 1st, 2nd, 3rd, 4th, and 5th of every month
• Total: 5 days × 24 hours × 60 minutes = 7,200 executions per month

Execution Time

This expression runs 7,200 times per month (5 days × 1,440 minutes per day) at:

• Every minute from 00:00 on the 1st to 23:59 on the 5th

Common Use Cases

1. Start-of-Month Intensive Monitoring

* * 1-5 * * /usr/local/bin/start-of-month-monitor.sh

Monitor system health or services intensively during the first 5 days of each month.

2. Start-of-Month Data Processing

* * 1-5 * * /usr/bin/python3 /scripts/process-start-of-month-data.py

Process data intensively during the beginning of each month.

3. Start-of-Month Queue Processing

* * 1-5 * * /usr/bin/node /app/process-queue.js

Process job queues or message queues intensively during the first 5 days.

4. Start-of-Month Cache Warming

* * 1-5 * * /usr/bin/python3 /scripts/warm-cache.py

Warm cache or pre-load data intensively during the start of each month.

Example Implementations

Start-of-Month Monitor Script

#!/bin/bash
# /usr/local/bin/start-of-month-monitor.sh

LOG_FILE="/var/log/start-of-month-monitor.log"
THRESHOLD_CPU=85
THRESHOLD_MEM=90

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. Resource Usage: Every-minute execution is very resource-intensive
2. Execution Time: Tasks must complete within 30-40 seconds
3. Error Handling: Implement comprehensive error handling and logging
4. Idempotency: Ensure tasks can run multiple times safely
5. Monitoring: Track execution time and failures closely
6. Limited Duration: Only runs for 5 days, then stops

When to Use

✅ Good for:

• Intensive start-of-month monitoring
• Start-of-month data processing
• Queue processing during critical periods
• Tasks needing frequent execution at month start

❌ Avoid for:

• Heavy computations
• Long-running processes
• Tasks requiring more than 30 seconds
• Operations needing full-month coverage

Related Patterns

Conclusion

The * * 1-5 * * expression is perfect for intensive operations during the first 5 days of each month. It provides maximum frequency during critical start-of-month periods while automatically stopping after 5 days, making it ideal for intensive monitoring and data processing during peak monthly activity.