Cron is a time-based job scheduler used in Unix-like operating systems. A cron expression defines when a scheduled task should run, using five fields: minute, hour, day of month, month, and day of week. This tool parses any standard cron expression into plain English and shows when it will next run — useful for checking a schedule before deploying it, or decoding one you've inherited. The Build mode generates a valid expression from plain-language presets, covering the most common scheduling patterns.