Cron Expression Explainer

Paste any cron expression — standard 5-field or 6-field with seconds — and instantly see it explained in plain English and German. The tool also shows the next 5 scheduled execution times and a visual hour grid so you can spot gaps in your schedule at a glance.

What is a Cron Expression?

A cron expression is a compact string used by the Unix cron daemon (and dozens of modern schedulers like GitHub Actions, AWS EventBridge, Kubernetes CronJobs) to schedule recurring tasks. The five standard fields are:

┌───────────── minute (0–59)
│ ┌─────────── hour (0–23)
│ │ ┌───────── day of month (1–31)
│ │ │ ┌─────── month (1–12 or JAN–DEC)
│ │ │ │ ┌───── day of week (0–7, where 0 and 7 = Sunday, or SUN–SAT)
│ │ │ │ │
* * * * *

A sixth field for seconds (placed before minutes) is supported by Quartz Scheduler, AWS EventBridge Scheduler, and others.

Syntax Reference

Notation	Example	Meaning
`*`	`* * * * *`	Every minute
Number	`0 9 * * *`	At 09:00 daily
Range	`1-5 * * * *`	Minutes 1 through 5
Step	`/15 * * *`	Every 15 minutes
List	`0,30 * * * *`	At :00 and :30 of every hour
Range+Step	`0-30/10 * * * *`	Every 10 minutes between :00 and :30
Name	`0 0 * * MON`	Every Monday at midnight

@ Macro Shortcuts

Macro	Equivalent	Description
`@hourly`	`0 * * * *`	Once per hour
`@daily` / `@midnight`	`0 0 * * *`	Once per day at midnight
`@weekly`	`0 0 * * 0`	Once per week on Sunday
`@monthly`	`0 0 1 * *`	Once per month on the 1st
`@yearly` / `@annually`	`0 0 1 1 *`	Once per year on January 1st
`@reboot`	—	Once at system startup

Common Examples

Expression	Schedule
`/5 * * *`	Every 5 minutes
`0 * * * *`	Every hour
`0 9-17 * * 1-5`	Every hour from 09:00–17:00 on weekdays
`30 6 * * 1`	Every Monday at 06:30
`0 0 1,15 * *`	At midnight on the 1st and 15th of each month
`0 0 * * 0,6`	At midnight on Saturday and Sunday

Is My Data Private?

Yes. All parsing and scheduling runs in your browser with pure JavaScript — no data is sent to any server.

FAQ

What is a cron expression?

A cron expression is a compact, time-based scheduling notation used in Unix-like systems. It consists of five fields (minute, hour, day of month, month, day of week) that define when a job should run. Some implementations add a sixth field for seconds.

What does */15 mean in a cron expression?

*/15 is a "step" notation — the asterisk means "every", and /15 means "every 15th value". So */15 in the minutes field means "every 15 minutes" (at :00, :15, :30, :45).

What are @daily, @hourly, and other @ macros?

@daily, @hourly, @weekly, @monthly, @yearly, and @annually are convenient shorthand macros. @daily is equivalent to "0 0 * * *" (midnight every day), @hourly is "0 * * * *" (at minute 0 of every hour), and so on.

What is the difference between 5-field and 6-field cron?

Standard cron uses five fields: minute, hour, day of month, month, day of week. Some implementations (like AWS EventBridge, Quartz Scheduler) add a sixth field for seconds at the beginning. This tool supports both formats.