Cron expressions are compact but notoriously easy to get wrong — a single misplaced field can turn "every hour" into "once a year." This tool builds a valid five-field cron expression (minute, hour, day of month, month, day of week) from a plain form, so you don't have to memorize the syntax or count asterisks. As you set each field, you get an instant plain-English description of the schedule plus a preview of the next several run times, so you can confirm the expression does what you actually intend before you paste it into crontab, a CI pipeline, or a scheduled cloud function. Common presets (every minute, hourly, daily at midnight, weekly, monthly, yearly) are included as shortcuts. Everything is computed client-side in your browser.