Cron Expression Parser

Parse cron expressions into plain English, see the next 10 run times, and build expressions interactively.

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How to Parse Cron Expressions

Enter a five-field cron expression (minute, hour, day-of-month, month, day-of-week) and the tool instantly translates it into plain English and calculates the next 10 scheduled run times. This is invaluable for verifying that your cron job will fire when you expect. You can also use the interactive builder: select values from dropdowns for each field and the cron expression updates automatically. The builder is especially helpful if you are new to cron syntax or need to construct complex schedules with ranges and step values.

Understanding Cron Syntax

Cron uses five fields separated by spaces: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, where 0 is Sunday). Special characters include * (any), , (list), - (range), and / (step). For example, */15 9-17 * * 1-5 means every 15 minutes from 9 AM to 5 PM on weekdays. This tool supports standard five-field cron only (not the extended six-field format with seconds). All computation runs in your browser using JavaScript date arithmetic.

Frequently Asked Questions

No. This tool supports the standard five-field cron format used by crontab, systemd timers, and most scheduling libraries.

Run times are displayed in your browser's local timezone.

Currently, only numeric values are supported: 1-12 for months, 0-6 for days of week.

It will compute run times based on the expression. Impossible combinations like February 31 will simply never match and show no upcoming runs.