Cron decoder + generator
Read any cron expression in plain English, or describe a schedule and get valid cron back. Includes next-fire times and equivalent forms.
Cron is the standard format Unix-like systems use to schedule recurring jobs: five space-separated fields representing minute, hour, day of month, month, and day of week. The syntax is dense but unambiguous — once you can read it, you can express almost any schedule.
The Cron Decoder works in both directions. Paste an existing expression to read it out in English; or describe a schedule and get valid cron back, with next-fire times and any caveats (like end-of-month edge cases) flagged.
Frequently asked
Does this support 6-field cron (with seconds)?
We target the standard 5-field syntax used by GNU cron, anacron, and most schedulers. Quartz-style 6-field cron is supported in decode but flagged.
Why both 0 and 7 for Sunday?
Both are valid for day-of-week in standard cron — historical compatibility. The decoder will note which is used.
What about end-of-month edge cases?
Cron's day-of-month field doesn't know how many days a month has, so `31 * * * *` fires on the 31st only when one exists. The decoder flags these.