⏰ Cron Expression Generator

Build cron expressions visually with a form-based editor. Set minute, hour, day, month, and weekday fields. Preview next run times. Free online cron expression generator.

Minute 0–59

Hour 0–23

Day of Month 1–31

Month 1–12

Day of Week 0–7

* * * * *

Every minute

How to Use

Choose a preset or configure

Pick a common schedule preset (every minute, hourly, daily, weekly, monthly) or configure each field individually.

Read the live description

The cron expression and its plain-English description update instantly as you change any field.

Copy and deploy

Click Copy Expression to copy the cron string to your clipboard for use in crontab, cloud schedulers, or CI/CD.

Frequently Asked Questions

What is a cron expression? +

A cron expression is a string used to define schedules for automated tasks (cron jobs). It has 5 fields: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-7). For example, "0 9 * * 1" means "every Monday at 9:00 AM".

What does * (asterisk) mean in a cron expression? +

* means "every" for that field. "* * * * *" means "every minute of every hour of every day". You can use */n for intervals — "*/15 * * * *" means "every 15 minutes".

What is the difference between day of month and day of week? +

Day of month (field 3) schedules tasks on specific dates like the 1st or 15th. Day of week (field 5) schedules on specific days like Monday or Friday. Using both fields in the same expression means "on this date OR this weekday" (OR, not AND).

How do I run a cron job every 5 minutes? +

Use "*/5 * * * *" — the */5 in the minute field means "every 5 minutes". Similarly, "*/30 * * * *" runs every 30 minutes, and "0 */2 * * *" runs every 2 hours at the top of the hour.

Can I test if my cron expression is correct? +

Yes — this generator shows a human-readable description of your cron expression in real-time, so you can immediately see if your schedule matches your intention before adding it to your server.

Complete Guide: Cron Expression Generator

Cron is a time-based job scheduler built into Unix-like operating systems. It lets you run scripts, commands, or programs automatically at specified intervals — from once a minute to once a year. A cron expression is a compact string that encodes a schedule, and understanding how to read and write these expressions is a fundamental skill for backend developers and system administrators.

The Five Fields of a Cron Expression

A standard cron expression contains exactly five fields separated by spaces:

┌───── minute (0 - 59)
│ ┌───── hour (0 - 23)
│ │ ┌───── day of month (1 - 31)
│ │ │ ┌───── month (1 - 12)
│ │ │ │ ┌───── day of week (0 - 7, 0 and 7 = Sunday)
│ │ │ │ │
* * * * *  command to execute

An asterisk (*) means "every possible value" for that field. So * * * * * runs the command every minute of every hour of every day.

Special Syntax: Lists, Ranges, and Steps

Cron expressions support powerful shorthand notations:

Lists: Comma-separated values run the job at each listed value. 0 9,17 * * * runs at 9:00 and 17:00 daily.
Ranges: A hyphen defines an inclusive range. 0 9-17 * * 1-5 runs every hour from 9 to 17 on weekdays.
Steps: A slash defines an interval. */5 * * * * runs every 5 minutes. 0 */2 * * * runs every 2 hours.

Special String Shortcuts

Most cron implementations also accept convenient named shortcuts instead of five-field expressions:

@reboot — Run once at startup
@daily or @midnight — Run once per day at 00:00
@weekly — Run once per week on Sunday at 00:00
@monthly — Run once per month on the 1st at 00:00
@yearly or @annually — Run once per year on January 1st
@hourly — Run at the start of every hour

Editing Your Crontab

The command crontab -e opens your personal crontab file in the default editor. Each non-comment line is one job. The command crontab -l lists your current jobs, and crontab -r removes them all. System-wide jobs can be placed in /etc/cron.d/ as separate files, which is preferred for packages and services because it avoids editing a single shared file.

Environment Variables in Crontab

Cron runs in a minimal environment — your usual $PATH is not set. It is best practice to define variables at the top of your crontab:

SHELL=/bin/bash
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=admin@example.com

0 3 * * * /usr/local/bin/backup.sh

Setting MAILTO causes cron to email job output to the specified address. Setting it to an empty string (MAILTO="") suppresses all email.

Capturing and Logging Output

By default, cron mails output to the user. To redirect output to a log file instead:

0 2 * * * /usr/local/bin/backup.sh >> /var/log/backup.log 2>&1

The >> appends stdout to the file, and 2>&1 redirects stderr to stdout so both streams end up in the same log. Use > instead of >> to overwrite the log each run.

Linux Cron vs macOS launchd

macOS uses launchd as its process scheduler, not cron (though cron is available for compatibility). launchd uses XML property list (.plist) files stored in ~/Library/LaunchAgents/ for user jobs. The key advantages of launchd over cron include missed-job catching (if the machine was off at scheduled time), richer conditions, and environment inheritance. For cross-platform scripts, cron remains the more portable choice.

To visualize an existing cron expression and understand what it means in plain English, use the Cron Visualizer.