ToolFoxCron Expression Explainer
Turn a 5-field cron expression into a plain-English sentence describing exactly when it runs.
At 09:00, Monday through Friday
How it works
A cron expression has five fields — minute, hour, day-of-month, month and day-of-week — each of which can be a wildcard (*), a single number, a comma-separated list, a range like 1-5, or a step like */15. The tool parses each field, validates it against that field's valid range (minutes 0-59, months 1-12 and so on) and composes a sentence describing the time of day and, separately, which days it applies to — using weekday names for day-of-week and "day N of the month" for day-of-month.
Example
The expression 0 9 * * 1-5 means minute 0, hour 9, every day-of-month, every month, weekdays Monday through Friday — which the tool renders as "At 09:00, Monday through Friday", the schedule for a typical weekday alert.
Frequently asked questions
What do 0 and 7 mean in the day-of-week field?
Both represent Sunday — this follows the standard cron convention where day-of-week can be written as 0-6 or 1-7, with 0 and 7 as aliases for the same day.
What happens with an invalid field, like a day-of-week of 99?
The tool reports an error naming exactly which field is invalid and why, rather than guessing at a schedule that does not exist.
Does it support step values like */15?
Yes — */15 in the minute field is read as "every 15 minutes", and a-b/n step ranges are supported too.
Does this run the schedule, or just explain it?
Just explain it — this tool only parses and describes the expression in your browser; it does not schedule or execute anything.
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