Cron Expression Guide

Learn how to create and understand cron expressions for scheduling tasks.

What is a Cron Expression?

A cron expression is a string consisting of five fields that represent a schedule. Each field represents a unit of time (minute, hour, day of month, month, day of week). Cron expressions are used to schedule recurring tasks in Unix-like operating systems.

Cron Expression Format

A standard cron expression has 5 fields:

┌───────────── minute (0 - 59)
│ ┌───────────── hour (0 - 23)
│ │ ┌───────────── day of month (1 - 31)
│ │ │ ┌───────────── month (1 - 12)
│ │ │ │ ┌───────────── day of week (0 - 7)
│ │ │ │ │
* * * * *

Special Characters

* (Asterisk)

Matches all values. For example, * in the hour field means every hour.

, (Comma)

Specifies multiple values. For example, 1,3,5 means on the 1st, 3rd, and 5th.

- (Hyphen)

Defines a range. For example, 1-5 means from 1 to 5.

/ (Slash)

Specifies increments. For example, */5 in minutes means every 5 minutes.

How to Use This Tool

  1. Use the visual builder on the left to set values for each field
  2. The cron expression will be generated automatically
  3. View the human-readable description of your expression
  4. Copy the expression to use in your crontab or scheduler