Paste any cron expression and CronTool shows the next scheduled runs on a real calendar. Visual is faster than mental math: spotting an unintended weekend fire, a missing weekday, or an end-of-month gap takes seconds, not the trial-and-error of grepping logs after the fact.
The viewer accepts standard 5-field crontab syntax plus 6- and 7-field extended cron used by AWS EventBridge, Vercel cron jobs, Quartz Scheduler and most major libraries. Toggle the extended-cron switch in the top bar to enable seconds, year, and the L/W/#/? modifiers.