Cron Expression Builder

What is a Cron Expression?

A cron expression is a string of five space-separated fields that tells a Unix system exactly when to run a scheduled task. The word "cron" comes from the Greek word for time, chronos, and the cron daemon has been a fundamental part of Unix and Linux systems since the 1970s.

Today, virtually every server environment, cloud platform, and web framework supports cron-based scheduling. Whether you need to clear a cache every hour, send a newsletter at 9am on weekdays, back up a database at midnight, or regenerate a sitemap weekly — cron is the standard tool for the job.

This builder generates cron expressions for 9 different platforms with platform-specific code snippets ready to copy directly into your project. It also shows the next 5 run times so you can verify your expression does exactly what you expect before deploying it.

The Five Fields of a Cron Expression

Field	Position	Allowed Values	Special Chars	Example
Minute	1st	0–59	* , - /	30 = at 30 mins past
Hour	2nd	0–23	* , - /	*/6 = every 6 hours
Day of month	3rd	1–31	* , - / ?	1 = 1st of month
Month	4th	1–12	* , - /	1-6 = Jan to Jun
Day of week	5th	0–6 (Sun=0)	* , - / ?	1-5 = Mon to Fri

Special Characters Explained

• * — matches any value. In the minute field, * means "every minute".
• */n — step value. */5 in the minute field means "every 5 minutes" (0, 5, 10, 15...).
• n-m — range. 1-5 in the day-of-week field means Monday through Friday.
• n,m,p — list of values. 1,3,5 means Monday, Wednesday and Friday.
• ? — no specific value. Used in AWS EventBridge when specifying day-of-month but not day-of-week, or vice versa.

Common Cron Expression Examples

Expression	Meaning	Typical Use Case
* * * * *	Every minute	Monitoring, polling APIs
*/5 * * * *	Every 5 minutes	WordPress cron, health checks
0 * * * *	Every hour	Cache clearing, hourly reports
0 0 * * *	Daily at midnight	Database backups, log rotation
0 9 * * 1-5	Weekdays at 9am	Business hour tasks, emails
0 0 1 * *	First of every month	Monthly reports, invoicing
0 0 * * 0	Every Sunday midnight	Weekly maintenance
0 */6 * * *	Every 6 hours	Data syncs, sitemap generation
30 4 1,15 * *	4:30am on 1st and 15th	Bi-monthly tasks
0 0 1 1 *	Once a year, Jan 1st	Annual cleanup

Platform-Specific Cron Syntax Guide

Unix / Linux / cPanel / Plesk

Standard Unix cron uses the classic five-field format. In cPanel, navigate to Advanced → Cron Jobs to enter your expression. Each line in the crontab has the format: MINUTE HOUR DAY MONTH WEEKDAY command. Edit your crontab from the command line with crontab -e and list existing jobs with crontab -l.

AWS EventBridge (formerly CloudWatch Events)

AWS EventBridge uses a modified cron syntax with three key differences: expressions must be wrapped in cron(...), a sixth Year field is added at the end, and the ? wildcard is required when specifying either day-of-month or day-of-week but not both simultaneously. All EventBridge schedules run in UTC.

Azure Functions (NCRONTAB)

Azure Functions uses NCRONTAB format which adds a Seconds field at the start. The standard five-field cron */5 * * * * becomes the six-field 0 */5 * * * * in Azure. The leading 0 means "at second 0 of each matching minute".

Kubernetes CronJobs

Kubernetes uses standard Unix cron syntax in the spec.schedule field of a CronJob manifest. The cron controller checks for CronJobs every 10 seconds. Note that jobs are not guaranteed to run at the exact scheduled time — they may be delayed if the controller was unavailable.

GitHub Actions Scheduled Workflows

GitHub Actions supports cron scheduling via the schedule event in your workflow YAML file. Schedules use standard UTC cron syntax, but the minimum interval is every 5 minutes. Scheduled workflows can be delayed by up to 15 minutes during periods of high load.

Laravel Task Scheduling

Laravel's scheduler uses a single cron entry running every minute: * * * * * php /path/to/artisan schedule:run. Individual tasks are defined in App\Console\Kernel using fluent helpers like ->everyFiveMinutes(), ->hourly(), ->daily(), and ->weekdays(), or raw cron with ->cron('expression').

WordPress Cron — WP-Cron vs Real Server Cron

WordPress includes a built-in scheduling system called WP-Cron, but it's "pseudo-cron" — it only runs when a visitor loads a page on your site. If your site receives no traffic at a scheduled time, the task won't run until the next page load. This is a fundamental reliability problem for production websites.

Problems with WP-Cron

• Scheduled tasks run late or not at all on low-traffic sites
• WP-Cron runs on every page load, adding overhead to every request even when no tasks are due
• Email newsletters and transactional emails may not send at the scheduled time
• Automated backups can be missed entirely during low-traffic periods
• E-commerce order processing and inventory updates can be delayed

The Solution: Disable WP-Cron and Use a Real Cron Job

Add define('DISABLE_WP_CRON', true); to your wp-config.php file, then set up a real server cron job to trigger WordPress's cron handler directly. Use the CMS tab in the builder above to get the exact command for your server setup.

A schedule of */5 * * * * (every 5 minutes) works well for most sites. For high-volume sites handling emails or order processing, a * * * * * (every minute) schedule is more appropriate.

Magento 2 Cron Configuration

Magento 2 relies on cron for critical operations: order processing, email sending, price rule updates, sitemap generation, and search indexing. Magento recommends running cron every minute (* * * * *) and letting Magento's internal job queue control individual task frequency. For large stores, running two separate cron entries — one for the default group and one for the index group — is strongly recommended.

Frequently Asked Questions