Cron Expression Generator

What Is the Cron Expression Generator?

Cron expressions schedule recurring tasks on Unix-like systems and countless cloud services (CI/CD pipelines, serverless functions, task schedulers) -- a compact 5-field syntax (minute, hour, day-of-month, month, day-of-week) that's notoriously easy to get backwards. This tool builds a valid expression from individual field values and describes the resulting schedule in plain English.

How to Use This Tool

Enter a value (a number or * for "any") in each of the 5 fields. The cron expression and a plain-English schedule description update instantly.

The 5 Cron Fields

Worked Example

Practical Uses

• Building a cron schedule for a CI/CD pipeline, cloud function, or cron job without memorizing field order
• Double-checking that a hand-written cron expression means what you think it does
• Learning cron syntax with an instant plain-English translation

To go the other direction -- decoding an existing cron expression -- use the Cron Expression Parser.

Common Patterns You Can Build Right Now

Each of the five boxes accepts a single value or an asterisk, and the tool joins them in order: minute, hour, day of month, month, day of week. Ranges, lists and step values are also allowed in the text boxes, because the tool inserts whatever you type as-is. Some patterns you can enter, all hypothetical schedules:

• Every day at 02:30: minute 30, hour 2, everything else an asterisk, giving 30 2 * * *.
• Every Monday at 08:00: minute 0, hour 8, day of week 1, giving 0 8 * * 1. In standard cron, 0 is Sunday and 1 is Monday.
• The first day of every month at midnight: minute 0, hour 0, day of month 1, giving 0 0 1 * *.
• Every 15 minutes: minute set to a step such as */15, hour an asterisk. The description text will not explain step syntax, but the expression itself is valid for most cron implementations.

Reading the Plain-English Description

The description is a simple summary, not a full interpreter. If minute and hour are both an asterisk it says every minute. If only the minute is set it says at that minute of every hour. Otherwise it prints the time as hours and minutes with a leading zero, then appends phrases for the day of month, month and weekday if those are not asterisks. Weekdays and months are shown as the numbers you typed, not as names. Ranges and steps typed into the boxes are shown literally rather than translated, so a value like */15 in the minute box will be treated as a specific minute in the sentence and read oddly. Trust the expression itself, and use the sentence as a rough check.

Important Gotchas

• Day of month and day of week interact. In many cron implementations, when both are set (neither is an asterisk), the job runs when either one matches, not only when both do. If you want the first Monday of a month, cron alone cannot express it; add a check inside your script.
• Cron uses the server's timezone, or whatever your scheduler is configured to use. A schedule of 09:00 means 09:00 in that zone, and daylight saving changes can skip or repeat runs around clock changes. Cloud schedulers often default to UTC, so confirm this in their documentation.
• The tool does not validate your entries. A minute of 75 or a month of 13 will still be output, so check each field against its allowed range: minutes 0 to 59, hours 0 to 23, day of month 1 to 31, month 1 to 12, weekday 0 to 6.
• This builds the five-field format. Some systems add a seconds field, a year field or names like MON and JAN, and some have their own dialect. Check the syntax your scheduler documents before deploying.

Frequently Asked Questions