Cron Expression Builder

Use this tool to visually construct any cron expression field by field — no memorization required. Each field offers five modes: Every (wildcard *), Specific (pick exact values), Range (from–to), Step (*/N), and Custom (free-form input). The generated expression updates in real time along with a plain-English description and the next five execution times.

Cron Field Reference

Field	Position	Range	Notes
Minute	1	0–59
Hour	2	0–23
Day of Month	3	1–31
Month	4	1–12	JAN–DEC names accepted
Day of Week	5	0–7	0 and 7 both = Sunday
Seconds	0 (opt.)	0–59	6-field cron only

Common Patterns

Expression	Meaning
`* * * * *`	Every minute
`/15 * * *`	Every 15 minutes
`0 * * * *`	Once per hour
`0 9 * * *`	Every day at 09:00
`0 9 * * 1-5`	Weekdays at 09:00
`0 9 * * 1`	Every Monday at 09:00
`0 0 1 * *`	First of every month at midnight
`0 0 1 1 *`	Once per year (January 1st)

Field Modes Explained

Every (*) matches all values in the field’s range — the job runs regardless of this field’s value.

Specific lets you choose one or more exact values. Multiple selections produce a comma-separated list, e.g. 1,15,30,45.

Range (from–to) matches every value between the two numbers, inclusive. Use 1-5 in the Day-of-Week field to target Monday through Friday.

Step (*/N) runs at every N-th value starting from the minimum. */5 in minutes means the job fires at :00, :05, :10, … :55.

Custom accepts any valid cron field string — useful for patterns like 1-5/2 (odd minutes between 1 and 5) or MON,WED,FRI.

Using the Generated Expression

Copy the expression and paste it into your crontab with crontab -e, or use the ready-made snippet EXPRESSION /path/to/script.sh. You can also use it with systemd timers, GitHub Actions schedules, AWS EventBridge, or any cron-compatible scheduler.

FAQ

What is a cron expression?

A cron expression is a compact scheduling notation used in Unix-like systems. It defines when a job should run using five fields: minute, hour, day of month, month, and day of week. Some systems add a sixth field for seconds.

What is the difference between cron-builder and cron-explainer?

The cron-builder lets you construct a cron expression from scratch using visual controls — select the mode (every, specific value, range, step) for each field. The cron-explainer works the other way: you paste an existing expression and it translates it into plain English.

What do the field modes mean?

Every (*) matches all values. Specific lets you pick one or more exact values. Range (e.g. 1–5) matches a continuous span. Step (*/N) matches every N-th value — */15 in minutes means every 15 minutes. Custom lets you type any valid cron field string directly.

How do I schedule a job to run on weekdays only?

Set the Day-of-Week field to Range mode with 1–5 (Monday through Friday). For example, "0 9 * * 1-5" runs at 09:00 every weekday. Use the "Weekdays 9am" preset to fill this in automatically.