Cron Expression Parser

How to Use the Cron Expression Parser

1. Enter a cron expression — Type or paste a standard 5-field cron expression in the input field. The format is: minute hour day-of-month month day-of-week (e.g., */5 * * * *).
2. Use presets — Click any preset button (Every 5 min, Hourly, Daily midnight, etc.) to quickly load a common cron expression and see how it works.
3. Read the description — A human-readable description appears instantly, explaining in plain English what the cron expression does (e.g., "Every 5 minutes").
4. Review the field breakdown — Each of the 5 fields is shown separately with its raw value, a plain-English explanation, and the valid range. This helps you understand each part of the expression.
5. Check next executions — The tool calculates and displays the next 10 execution times in your local timezone, so you can verify the schedule is correct.

Features

• Standard 5-field cron expression support (minute, hour, day, month, day-of-week)
• Human-readable description generated in plain English
• Field-by-field breakdown with range information and error messages
• Next 10 execution times calculated from current local time
• 6 common presets: every 5 min, hourly, daily, weekly, monthly, weekdays 9-5
• Supports ranges (1-5), steps (*/5), lists (1,3,5), and combined syntax (1-5/2)
• Month names (JAN-DEC) and day-of-week names (MON-SUN) accepted
• Real-time validation with clear error messages for invalid expressions
• 100% client-side — no expressions are sent to any server
• Responsive design — works on desktop and mobile

Understanding Cron Expressions

Common Use Cases

Cron Expression Tips

• Always test your cron expression with the parser before deploying. A small mistake like using 0-6 instead of 1-5 in the day-of-week field can cause tasks to run on the wrong days.
• Use the next execution times to verify your schedule. If you expect a task to run on weekdays but see Saturday times in the list, the expression needs adjustment.
• When both day-of-month and day-of-week are specified, most cron implementations use OR logic (run if either matches). If you need AND logic, check your specific cron implementation's documentation.
• For tasks that need to run at a specific timezone, set the TZ environment variable in your cron environment. The parser shows times in your browser's local timezone.
• Common mistake: using * in the day-of-month field when you only want to run on specific days of the week. Remember that * means 'every day', so pair it with the correct day-of-week value.
• After understanding a cron expression, you might need to convert the execution times. Use Timestamp Converter to convert between time formats and timezones.