Cron Expression Generator
Build a five-field cron expression, read it in plain English, and preview the next run times. Nothing is uploaded — it runs on your device.
Why a cron builder helps
Cron syntax is compact but easy to get wrong: five fields in a fixed order (minute, hour, day of month, month, day of week), each accepting an asterisk, a range, a list or a step. A typo silently changes when a job runs. This tool assembles the fields for you, writes the expression, explains it in plain English and previews the next five runs, so you can confirm the schedule before you deploy it to a server or a scheduler. The day-of-week field accepts both 0 and 7 for Sunday. Related browser-only tools: format structured data with the JSON formatter, compare two texts with the line sorter, and count a draft with the word counter.
Frequently asked questions
What is a cron expression?
A cron expression is five space-separated fields - minute, hour, day of month, month and day of week - that describe when a scheduled task should run, for example 0 9 * * 1-5 for 09:00 on weekdays.
What do the asterisk and slash mean?
An asterisk (*) means every value for that field. A slash adds a step, so */15 in the minutes field means every 15 minutes. You can also use ranges like 1-5 and lists like 1,3,5.
Does it explain the expression in plain English?
Yes. As you build the five fields it writes the expression and a plain-language description, such as "At 09:00 on every day-of-week from Monday through Friday".
Does it show when the job would next run?
Yes. It lists the next five run times in your local time zone, stepping through the schedule so you can sanity-check it before deploying.
Is my input sent anywhere?
No. Building, explaining and previewing all happen in your browser with built-in JavaScript. Nothing is uploaded.
Does the day-of-week field accept 0 or 7 for Sunday?
Yes. Both 0 and 7 are treated as Sunday, matching the usual cron convention.