What is a cron expression?

A cron expression is a five-part string that tells cron when to run a scheduled job. The five positions represent minute, hour, day of month, month, and day of week. Each field can use wildcards, ranges, lists, or step values to define complex schedules.

How do I run a job every N minutes?

Use the step syntax in the minutes field: */N * * * *. For example, */5 * * * * runs every 5 minutes and */15 * * * * runs every 15 minutes. Combine with hour or day filters if you only want the job during specific hours.

How can I schedule cron on weekdays at 9:30?

Use 30 9 * * 1-5. This fires at 09:30 from Monday (1) through Friday (5). The day-of-month field stays as * so the day-of-week filter controls when it runs.

Does cron support timezones?

Classic Linux cron uses the server's timezone. Some platforms (like Kubernetes CronJob or GitHub Actions) let you specify a timezone. Our generator previews upcoming runs in any timezone so you can verify how the schedule behaves globally.

Cron Expression Generator – Crontab Builder

Quick Start: Choose a common schedule

Or customize each field below for advanced scheduling

How to build a cron schedule in minutes

Cron expressions look cryptic, but they follow a simple five-field pattern. Enter values for minute, hour, day of month, month, and day of week. Combine ranges (1-5), comma lists (1,15), or step values (*/10) to match the exact cadence you need.

The generator above pairs each field with helper buttons, so you can jump straight to popular schedules like “every 5 minutes” or “weekdays at 09:30.” A plain-English summary and timezone-aware preview confirm the schedule before you paste it into production.

Understanding the five cron fields

Field	Order	Allowed values	What it controls	Example values
Minute	1st	0-59	When within the hour the job runs.	`0 · */5 · 15,45`
Hour	2nd	0-23	Hour of the day in 24h format.	`0 · 6-18 · */2`
Day of month	3rd	1-31	Specific days inside the month.	`1 · 1,15 · 25-31`
Month	4th	1-12 or JAN-DEC	Months of the year.	`* · 1,4,7,10 · 4-9/2`
Day of week	5th	0-6 or SUN-SAT	Days of the week (0 and 7 are Sunday).	`* · 1-5 · 0,6`

Workflow tips for teams

Use the presets as a starting point, then tweak individual fields. This prevents typos in long expressions like15 1 1 1,4,7,10 *.
Verify the timezone preview to make sure the schedule aligns with your deployment region or product SLA.
Copy the formatted snippets (Linux, Docker, GitHub Actions) directly into your automation scripts to avoid quoting mistakes.

Popular cron recipes

Cache warmers: 0 */2 * * * refreshes caches every two hours.
Business reports: 30 7 * * 1-5 sends weekday dashboards at 07:30.
Nightly backups: 0 2 * * * runs at 02:00 server time.
Last-day billing: 0 9 25-31 * * attempts from the 25th through the end of each month.

Integrating cron with your toolchain

Storing schedules in version control keeps ops knowledge close to the code. If you are building CI/CD automations, the Git tooling guide covers popular runners and hosted solutions that read straight from cron syntax. Front-end teams who rely on scheduled UI updates can pair cron jobs with React’s data fetching patterns—our guide to shows how to sync background jobs with client-side refreshes.

Best practices for reliable cron jobs

Cron Expression Generator — Crontab Schedule & Examples