How to Schedule Tasks with Cron on Linux

What Is Cron?

Cron is Linux's built-in job scheduler. It runs commands or scripts automatically at times you define — every minute, every day at 3 AM, the first of every month, or any schedule you can imagine. It is the go-to tool for automating backups, log rotation, syncing files, and any repetitive task.

Editing Your Crontab

Each user has their own crontab (cron table). Edit it with:

crontab -e

This opens your crontab in the default editor. Each line is one scheduled job.

Crontab Syntax

Every cron line has five time fields followed by the command:

# ┌───────────── minute (0–59)
# │ ┌─────────── hour (0–23)
# │ │ ┌───────── day of month (1–31)
# │ │ │ ┌─────── month (1–12)
# │ │ │ │ ┌───── day of week (0=Sun, 6=Sat)
# │ │ │ │ │
# * * * * *  command-to-run

Use * to mean "every". Use commas for lists (1,15), hyphens for ranges (1-5), and slashes for intervals (*/10 = every 10).

Common Schedule Examples

# Every day at 2:30 AM
30 2 * * * /home/alice/backup.sh

# Every hour
0 * * * * /usr/bin/python3 /home/alice/sync.py

# Every 10 minutes
*/10 * * * * /home/alice/check.sh

# Every Monday at 9 AM
0 9 * * 1 /home/alice/weekly-report.sh

# First day of every month at midnight
0 0 1 * * /home/alice/monthly-cleanup.sh

Handy Shortcuts

Cron also supports these readable aliases:

• @reboot — run once at startup
• @hourly — equivalent to 0 * * * *
• @daily — equivalent to 0 0 * * *
• @weekly — equivalent to 0 0 * * 0
• @monthly — equivalent to 0 0 1 * *

Viewing and Managing Cron Jobs

# List your cron jobs
crontab -l

# Remove all your cron jobs (careful!)
crontab -r

Tips for Reliable Cron Jobs

• Use absolute paths for commands and files — cron has a minimal environment
• Redirect output to a log: command >> /var/log/myjob.log 2>&1
• Test your script manually before scheduling it
• Use crontab.guru to verify your schedule expressions