What is a cron expression?

A cron expression is a string of five space-separated fields (minute, hour, day-of-month, month, day-of-week) that tells the cron daemon when to run a job. For example, "0 2 * * *" means every day at 2:00 AM.

What does the asterisk (*) mean?

An asterisk means "every possible value" for that field. "* * * * *" runs every minute, every hour, every day.

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

Day-of-month (field 3) is a calendar date like the 1st or 15th. Day-of-week (field 5) is a named day like Monday or Friday. Most cron implementations run the job when EITHER condition is met if both are set to non-wildcard values.

How do step values like */15 work?

A step value means "every N units". "*/15" in the minute field means every 15 minutes (0, 15, 30, 45). You can also use a range with a step, like "0-30/5".

Does this tool support seconds?

Standard Unix/Linux cron uses 5 fields (no seconds). Some systems like Quartz or AWS EventBridge use 6-field expressions. This tool generates standard 5-field cron expressions compatible with crontab, GitHub Actions, and most job schedulers.

Are the next-run times in UTC or local time?

The next-run preview uses your browser's local time zone. When deploying a cron job on a server, confirm the server's time zone matches your intended schedule.

Cron Expression Generator

Name: Cron Expression Generator
Availability: InStock
Author: Nham Vu

Build cron expressions visually, get a plain-English description, and preview the next 5 scheduled run times.

Quick Presets

Field Editor

Minute (0–59)

Hour (0–23)

Day of Month (1–31)

Month (1–12)

Day of Week (0=Sun … 6=Sat)

Or type expression directly

Cron Expression

* * * * *

Minute

Hour

Day/Month

Month

Day/Week

Human-Readable Description

Next 5 Run Times (your local time)

Copied!

Summary

Build cron expressions visually, get a plain-English description, and preview the next 5 scheduled run times.

How it works

Choose a preset schedule or start from the custom fields.
Adjust the minute, hour, day, month, and weekday selectors.
The cron expression updates in real time as you make changes.
Read the human-readable description to confirm the schedule is correct.
Review the next 5 run times for additional assurance.
Click "Copy Expression" to paste it into your crontab or CI config.

Use cases

Schedule a nightly database backup at 2:00 AM.
Run a cache-clearing script every 15 minutes.
Trigger a weekly report email every Monday at 8:00 AM.
Configure CI/CD pipelines with accurate cron triggers.
Set up health-check pings at regular intervals.
Build data-sync jobs that run on specific days of the month.
Generate crontab lines for server maintenance windows.
Verify an existing cron expression with the human-readable preview.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu