All tools on CronProbe
Everything on this site runs 100% in your browser. No uploads, no accounts, nothing sent anywhere.
CronProbe (main tool)
Free, 100% client-side crontab checker. Translate cron syntax into plain English, calculate upcoming run times, check a whole crontab file, and see runs in any time zone including DST gaps.
Crontab File Checker
Paste a whole crontab and check every line: invalid schedules with the exact field at fault, unescaped % signs that cron turns into newlines, commands with no path, empty MAILTO, and day-of-month/day-of-week OR surprises. Runs in your browser.
Cron Next Runs in Any Time Zone
See when a cron expression fires in any IANA time zone, alongside UTC, and which scheduled times are skipped by a daylight-saving gap. Checked against known DST transition dates. Runs in your browser.
Looking for explanations rather than a tool? CronProbe guides cover 3 worked examples and gotchas.
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