Fill in the five cron? fields, pick a preset, and get a plain-English description plus a preview of the next run times. Copy the expression with one click. Nothing leaves your browser.
Lots of computer systems can run a job on a repeating schedule — email a report every Monday morning, back up files at midnight, tidy a folder every hour. The catch is that the schedule has to be written as a cryptic five-part code, and getting one character wrong means the job runs at the wrong time or never.
Build it here instead: click a preset or fill in the boxes, read back the plain-English meaning, and sanity-check the list of upcoming run times before you paste it anywhere.