What are the 5 fields in a cron expression?

The five fields, in order, are: minute (0–59), hour (0–23), day of month (1–31), month (1–12 or JAN–DEC), and day of week (0–6 or SUN–SAT, where 0 = Sunday). Each field can contain a single value, a range (1-5), a list (1,3,5), a step value (*/15), or an asterisk (*) meaning "every." For example, "30 2 1 * *" runs at 2:30 AM on the 1st of every month.

Can I use day names (SUN, MON) instead of numbers?

Yes. The day-of-week field accepts three-letter abbreviations: SUN, MON, TUE, WED, THU, FRI, and SAT. Similarly, the month field accepts JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, and DEC. You can mix names with ranges and lists — for example, "0 0 * * MON-FRI" is equivalent to "0 0 * * 1-5". The Cron Generator normalizes these automatically when you type them in.

What does */5 mean in a cron expression?

The */N syntax is a step value. It means "every N units starting from the minimum value of the field." In the minute field, */5 means every 5 minutes (0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55). In the hour field, */2 means every 2 hours (0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22). You can also use a base range with a step, like 1-10/2, which means 1, 3, 5, 7, 9.

How many upcoming run times can I preview?

The Cron Generator shows the next 5 scheduled run times based on your current cron expression. The tool calculates these from the current date and time, walking forward through the schedule to find the next matching times. The preview updates automatically whenever you change the expression. Note that the calculation searches up to 2 years ahead, which covers all practical scheduling needs.

Does it support 6-field cron (with seconds)?

No. This Cron Generator works with the standard 5-field cron format: minute, hour, day of month, month, and day of week. Some modern implementations (like Quartz Scheduler or Spring Cron) add a sixth field for seconds at the beginning, and some add a seventh for years. These are non-standard extensions. If you need 6-field cron support, you can manually prepend a seconds field to the generated expression.

Can I generate cron for specific timezones?

The Cron Generator produces timezone-agnostic cron expressions. The expression itself just defines the pattern — the actual timezone depends on the system or scheduler that interprets it. Most Unix cron daemons use the server's local timezone. Cloud schedulers like AWS EventBridge or Kubernetes CronJobs let you specify a timezone separately. The next-run preview in this tool uses your browser's local timezone.

Does it work on mobile?

Yes. The Cron Generator is fully responsive and works on phones, tablets, and desktops. The visual builder adapts to smaller screens with stacked layouts, and all inputs are touch-friendly with a minimum 44px tap target. Dark mode is supported and follows your system or browser preference. You can build, copy, and preview cron expressions on any device.

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Cron Generator

Generate cron expressions with a visual builder and human-readable preview.

What is a Cron Expression?

A cron expression is a compact string that defines a recurring schedule. It tells a scheduler — typically the Unix cron daemon — exactly when to run a command or script. The format has been a cornerstone of Unix-like operating systems since the late 1970s, when Ken Thompson introduced it in Version 7 Unix. Today, cron expressions are used far beyond the original cron daemon: they appear in CI/CD pipelines (GitHub Actions, GitLab CI), cloud schedulers (AWS EventBridge, Google Cloud Scheduler, Azure Functions), job orchestration tools (Airflow, Kubernetes CronJobs, Nomad), and countless application frameworks that need recurring task support.

A standard cron expression consists of five fields separated by spaces, read left to right:

Minute (0–59) — which minute of the hour
Hour (0–23) — which hour of the day
Day of Month (1–31) — which day of the month
Month (1–12 or JAN–DEC) — which month of the year
Day of Week (0–6 or SUN–SAT) — which day of the week

Each field can hold a single value (5), a range (1-5), a list (1,3,5), a step value (*/15), or a wildcard (*) meaning "every possible value." These building blocks combine to express schedules ranging from "every minute" to "at 3:30 AM on the second Tuesday of March" (though the latter requires the # extension, which not all cron implementations support).

Common use cases for cron scheduling include automated backups (nightly database dumps), log rotation(compressing and archiving old logs), report generation(weekly summary emails), certificate renewal(Let's Encrypt's certbot), database maintenance (vacuum, index rebuilds), CI/CD pipeline triggers (nightly test runs), and data sync jobs (periodic API polling or ETL tasks). Essentially, any task that needs to run on a predictable, repeating schedule is a candidate for cron.

While cron expressions are powerful, they're also notoriously hard to read at a glance. 0 9 * * 1-5doesn't immediately communicate "9 AM on weekdays" to most people. That's where a Cron Generator comes in: it provides a visual interface to build expressions and translates them into human-readable descriptions, bridging the gap between machine-readable schedules and human understanding.

How to Use the Cron Generator

Choose a preset from the dropdown to start with a common schedule (every 5 minutes, daily at 9 AM, weekdays, etc.). You can also build from scratch by editing each field.
Configure each fieldusing the quick-option buttons next to each input. Choose "Every" for wildcard (*), type a specific value, a range (1-5), or a step value (*/15). The month and day-of-week fields also support name selectors (JAN–DEC, SUN–SAT).
Watch the generated cron expression update in real time in the large monospace display. Click Copy to copy it to your clipboard.
Read the human-readable description below the expression — it automatically translates the cron syntax into plain English.
Check the next 5 run times preview to see exactly when your schedule will fire, starting from now.
Alternatively, switch to manual edit mode by typing a cron expression directly into the expression field. The builder fields and description will update automatically to reflect your input.
Click Clear to reset all fields to their default values and start over.

Cron Expression Format

A cron expression is written as five fields separated by spaces:minute hour day-of-month month day-of-week. Below is a detailed breakdown of each field and the special characters you can use.

Minute (0–59)

The minute field specifies which minute(s) of the hour the task runs. * means every minute. 5 means at minute 5. 0,15,30,45 means at those four minutes. */10 means every 10 minutes (0, 10, 20, 30, 40, 50). 10-20 means every minute from 10 through 20.

Hour (0–23)

The hour field uses a 24-hour clock. 0 is midnight, 12 is noon, 23 is 11 PM. * means every hour. 9-17 means every hour from 9 AM to 5 PM. */2 means every 2 hours.

Day of Month (1–31)

Specifies the day of the month. 1 means the 1st. 15 means the 15th. *means every day of the month. Note that months with fewer than 31 days simply won't match days that don't exist (e.g., 31won't fire in February).

Month (1–12 or JAN–DEC)

Specifies the month. You can use numbers (1 = January, 12 = December) or three-letter abbreviations (JAN, FEB, …, DEC). * means every month. 6-8 means June through August.

Day of Week (0–6 or SUN–SAT)

Specifies the day of the week. 0 (or SUN) is Sunday, 6 (or SAT) is Saturday. * means every day. 1-5 means Monday through Friday. 0,6 means weekends.

Special Characters

*

Wildcard— matches every value in the field's range. In the minute field, * means 0 through 59.

,

List separator — specifies multiple individual values. 1,5,10 means 1, 5, and 10.

-

Range — specifies all values between two bounds (inclusive). 1-5 means 1, 2, 3, 4, 5.

/

Step value — specifies intervals. */15 means every 15 values from the field minimum. 1-10/2 means 1, 3, 5, 7, 9.

#

Nth weekday (extension, not in standard cron) — specifies the Nth occurrence of a day in a month. 5#3 means the third Friday of the month. Not all cron implementations support this.

Common Cron Examples

Expression	Description
* * * * *	Every minute
/5 * * *	Every 5 minutes
/15 * * *	Every 15 minutes
0 * * * *	Every hour at minute 0
0 0 * * *	Every day at midnight (00:00)
0 9 * * *	Every day at 9:00 AM
0 9 * * 1-5	At 9:00 AM, Monday through Friday
0 0 * * 0	Every Sunday at midnight
0 0 1 * *	On the 1st of every month at midnight
0 0 1 1 *	At midnight on January 1st (New Year's)
30 3 * * *	Every day at 3:30 AM (common for backups)
0 17 * * 0	Every Sunday at 5:00 PM
0 9,12,18 * * *	At 9:00 AM, 12:00 PM, and 6:00 PM every day

Features

Visual builder — configure each of the five cron fields with quick-option buttons for common patterns (every, specific, range, step).
Human-readable descriptions — the tool automatically translates cron syntax into plain English, so you always know what your schedule means.
Preset library — start from 10 common scheduling patterns including every 5 minutes, daily at midnight, weekdays at 9 AM, and monthly runs.
Manual edit mode — type a cron expression directly and the builder fields, description, and run-time preview update automatically.
Next run times preview — see the next 5 scheduled execution times calculated from the current moment, so you can verify your schedule behaves as expected.
Named tokens — use JAN–DEC for months and SUN–SAT for days of the week, making expressions more readable.
Copy to clipboard — one-click copy of the generated expression for pasting into crontab, CI/CD configs, or scheduler dashboards.
Input validation — out-of-range values, invalid syntax, and malformed expressions are caught instantly with clear error messages.
100% client-side — all computation happens in your browser. No data is sent to any server.
Responsive design — works on mobile, tablet, and desktop with full dark mode support.

Frequently Asked Questions