Cron Expression Generator

About this tool

Cron Expression Generator on UtilityKit builds 5-field cron expressions through a point-and-click interface — no memorizing field order or step syntax. Cron is the standard scheduling mechanism on Linux and Unix, used by crontab, GitHub Actions on.schedule, Kubernetes CronJobs and many CI/CD platforms. The five fields — minute, hour, day of month, month, and day of week — accept specific values and step syntax (*/5), but the rules are easy to get wrong from memory. This tool replaces memorization with dropdowns: pick a value per field, watch the expression assemble live, and read a plain-English summary of the chosen options. Each dropdown offers a fixed set of common values: minute 0, 15, 30 or 45 or every 5 or 10 minutes; a few set hours or every 2 hours; the 1st or 15th of the month; January, April, July or December; and any single weekday. Copy the expression from the read-only field and paste it into a crontab line, YAML workflow, or Terraform resource.

Why use it

• Visual Field-by-Field Builder: Dropdowns for each of the five cron fields eliminate the need to memorize field order or step syntax — the correct expression assembles automatically as you select options.

• Plain-English Schedule Explanation: Every change to a dropdown immediately updates a human-readable description of when the schedule runs — so you can confirm 'Runs with schedule: Every 5 minutes, Every hour, Every day…' before copying.

• Fewer Typing Errors: The builder assembles the expression from its preset options, so field order and step syntax are always right. One exception: 'Last day (Unix-like)' inserts L, which standard 5-field cron does not accept.

• Covers All Five Standard Fields: Minute, hour, day of month, month, and day of week are all configurable — the same 5-field format used by Linux crontab, GitHub Actions, Kubernetes CronJobs, and AWS EventBridge.

• Easy to Copy: The generated expression sits in a read-only field you can select and copy — paste it directly into a crontab line, YAML workflow, or Terraform resource without reformatting.

• No Installation, No Sign-Up, Works Offline: The builder runs entirely in the browser. There is no library to install, no account to create, and no Internet connection required after the page loads.

How to use

1. Select a value from the Minute dropdown — choose 'Every minute' for * or pick a specific minute or step like 'Every 5 minutes' for */5.
2. Select a value from the Hour dropdown — choose 'Every hour' for *, a specific hour (e.g. '09:00'), or a step like 'Every 2 hours' for */2.
3. Select a value from the Day of month dropdown — choose 'Every day' for *, Day 1 or Day 15, or 'Last day (Unix-like)', which inserts L (not accepted by standard cron).
4. Select a value from the Month dropdown — choose 'Every month' for *, or January, April, July or December.
5. Select a value from the Day of week dropdown — choose 'Any day' for * or a specific weekday (Monday through Sunday).
6. Copy the generated expression from the output field and paste it into your crontab, GitHub Actions workflow, AWS EventBridge rule, or any other cron-compatible scheduler.

When it helps

• When setting up a cron job on a Linux server and you want to verify the expression before writing it to the crontab to avoid an off-by-one scheduling mistake.
• When writing a GitHub Actions workflow with an on.schedule trigger and need the correct cron string for a specific weekday-and-time pattern.
• When configuring an AWS EventBridge rule, a Kubernetes CronJob, or a Heroku Scheduler entry and the UI accepts a raw cron expression.
• When you need a monthly or yearly schedule, such as 09:00 on the 1st of each month or midnight on 1 January, and want the field order right.
• When scheduling a recurring backup, report, or cleanup job and need to quickly try different frequencies (every 5 minutes vs every hour vs nightly) to pick the right cadence.
• When onboarding a teammate who is unfamiliar with cron syntax and you want to show them a live-updating builder that makes the five-field format intuitive.

Examples

Minute: 0, Hour: 0, Day: *, Month: *, Weekday: *

0 0 * * * — runs at 00:00 every day (server timezone)

Minute: 0, Hour: 9, Day: *, Month: *, Weekday: Monday

0 9 * * 1 — runs at 09:00 on every Monday

Minute: */5, Hour: *, Day: *, Month: *, Weekday: *

*/5 * * * * — runs at minutes 0, 5, 10, 15 … 55 of every hour

Tips

• GitHub Actions schedules run on UTC. If you want a job at 9 AM Eastern (UTC-5), set the hour field to 14 — and remember to adjust by 1 hour during daylight saving time (set to 13 for EDT, UTC-4).
• Avoid scheduling expensive jobs at exactly midnight (0 0 * * *) — many systems do the same and server load spikes. Offset by a few minutes (e.g. 5 0 * * *) to spread the load.
• To run a job on the last day of every month, the 'Last day' preset generates the L value. Note that L is a Quartz extension; standard Linux cron does not support it — use 28 or a wrapper script instead for maximum compatibility.
• The plain-English explanation below the expression is the quickest way to sanity-check a schedule before deploying. Read it aloud: 'Runs with schedule: Every 5 minutes, Every hour, Every day…' confirms the cadence immediately.
• For a weekday-only schedule (Monday to Friday), pick any single weekday, copy the expression, and change the last field to 1-5 by hand — standard cron accepts ranges, but the dropdown offers only single days.

Frequently Asked Questions

Glossary

Cron expression

A string of five space-separated fields that specifies a recurring schedule for a cron job. The fields in order are: minute, hour, day of month, month, and day of week.

Wildcard (*)

In a cron field, * means 'every valid value'. For example, * in the hour field means 'every hour from 0 to 23'.

Step syntax (*/N)

Divides the valid range by N and triggers at each step. For example, */15 in the minute field triggers at 0, 15, 30, and 45 — every 15 minutes.

Crontab

The file (or the crontab -e editor command) on a Linux or Unix system where cron jobs are defined. Each line contains a 5-field schedule expression followed by the command to run.

UTC offset

The difference in hours between a local timezone and Coordinated Universal Time. Cloud schedulers typically operate on UTC, so hour-based cron expressions must account for the offset between UTC and the intended local time.

5-field cron format

The standard Unix cron format with fields for minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–6, Sunday=0 or 7). Used by Linux cron, GitHub Actions, Kubernetes CronJobs, and most schedulers.