Build, read in plain English and simulate cron expressions: Unix, Quartz and AWS EventBridge.
Cron is a classic topic for automation, server jobs and recurring tasks, but the real questions usually appear in the details: what each field means, how to express weekdays only, what changes between 5-field Unix cron, 6-field Quartz and the AWS syntax, and why a valid expression may still run at a time you did not expect. This tool builds the expression through visual controls, translates the result into plain English, points at the offending field, lists the next runs in the time zone you pick and generates the matching crontab line, CronJob manifest or EventBridge rule.
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/cron-generator"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Cron Generator"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
Yes, and 6-field ones too. It creates expressions through the visual builder, validates each field with a specific message (out of range, invalid step, reversed range, a day that does not exist in the month), translates the expression into plain English and previews the next runs.
every 5 minutes, every day
No run found inside the simulated window.
Base: wall clock in UTC. Times skipped or repeated by daylight saving are flagged.
*/5 * * * * /usr/local/bin/backup.sh
Parsing, simulation and conversion run in your browser. No schedule is sent to a server.