Cron Expression Builder

Paste a 5-field cron expression and get a plain-English explanation of when it runs — handy for scheduling scripts and cron jobs.

Cron syntax has powered scheduled tasks on Unix-like systems since the 1970s, and it has aged into one of those pieces of technology that's simultaneously indispensable and genuinely hard to read at a glance. Five fields — minute, hour, day of month, month, day of week — packed into a compact string like "0 9 * * 1-5" can express a surprisingly wide range of schedules, but that compactness is exactly what makes it unreadable without practice: the difference between an asterisk, a comma-separated list, and a slash-based step value changes the meaning entirely, and there's no visual cue distinguishing them at a glance.

That gap between "compact and powerful" and "readable by a human who didn't write it" is precisely the problem a cron translator exists to close. Almost every developer who works with cron regularly still has to stop and think, or check documentation, when reading someone else's schedule string — it's rarely intuitive even after years of occasional use, because the format prioritizes machine parsing over human clarity.

This tool works in the more commonly needed direction: paste in a cron expression, and it translates the five fields into a plain-English description of when the job will actually run, catching the kind of misread schedule that could otherwise mean a script runs at 9am instead of 9pm, or every day instead of only on weekdays.

1. Enter a cron expression in the format: minute hour day-of-month month day-of-week.
2. Press Explain.
3. Read the plain-English summary of when the job runs.