CronLens
Translate a cron expression to plain English and preview its next 10 run times. Everything is computed in your browser.
Cron expression
*****Next 10 runs
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How cron expressions work
A cron expression has 5 fields — minute hour day-of-month month day-of-week — each field a number, a range, a comma list, a step, or * (any value), per the Vixie Cron / POSIX standard:
0 9 * * 1-5 → minute 0, hour 9, any day of month, any month, Monday(1) through Friday(5) → "At 9:00 AM, Monday through Friday"
One rule trips up a lot of people: if both day-of-month and day-of-week are restricted (not *), cron runs the job when either field matches — not only when both match at once. So 0 0 1 * 5 means "midnight on the 1st of the month, OR every Friday at midnight," not "only Fridays that happen to be the 1st." CronLens implements this exact OR rule.
Frequently asked questions
What format does CronLens expect?
Standard 5-field Vixie cron: minute, hour, day of month, month, day of week. It supports *, lists (1,15), ranges (1-5) and steps (*/15).
What happens if both day of month and day of week are set?
Per the cron standard, when both fields are restricted (not *), the job runs when EITHER one matches, not only when both match at once. CronLens follows this rule exactly.
What timezone are the next-run times shown in?
Your browser's local timezone, which is labeled above the list. Cron itself has no concept of timezone — it always runs in the timezone of the machine executing it.
Does it support 6-field cron with seconds, or @daily-style shortcuts?
Not currently. CronLens targets standard 5-field cron, the format used by crontab, most CI schedulers and Kubernetes CronJobs.