What is a cron expression?

A cron expression is a string of 5 fields (minute, hour, day, month, weekday) that defines when a task should run. Example: '0 9 * * 1-5' means 9 AM on weekdays.

What does each field mean?

Fields: Minute (0-59), Hour (0-23), Day of month (1-31), Month (1-12), Day of week (0-7, where 0 and 7 are Sunday).

What's the difference between * and ? in cron?

Both mean 'any value', but * is used in day-of-month or month fields, while ? is used in day-of-week field when you specify day-of-month (they're mutually exclusive).

How do I run a task every X minutes/hours?

Use */X syntax. '*/15 * * * *' runs every 15 minutes. '0 */2 * * *' runs every 2 hours at minute 0.

Can I use this for cloud platforms?

Yes, many platforms use cron syntax: AWS EventBridge, Google Cloud Scheduler, Azure Functions, GitHub Actions, and more support cron expressions.

Runs entirely in your browser

Cron Expression Generator

Build and understand cron expressions visually. Schedule tasks for Linux, macOS, or any cron-compatible system.

Generated Expression

Minute

Hour

Day (M)

Month

Day (W)

Human Readable:

At minute 0 of every hour

Configure Schedule

Minute0-59

Hour0-23

Day (M)1-31

Month1-12 or JAN-DEC

Day (W)0-6 or SUN-SAT

Next Execution Times

1.Fri, Oct 30, 202613:00in 16m

2.Fri, Oct 30, 202614:00in 1h 16m

3.Fri, Oct 30, 202615:00in 2h 16m

4.Fri, Oct 30, 202616:00in 3h 16m

5.Fri, Oct 30, 202617:00in 4h 16m

Common Presets

Cron Syntax Reference

Field	Allowed Values	Special Characters
Minute	0-59	* , - /
Hour	0-23	* , - /
Day (M)	1-31	* , - / ? L W
Month	1-12 or JAN-DEC	* , - /
Day (W)	0-6 or SUN-SAT	* , - / ? L #

key 'cronGenerator.specialChars (en)' returned an object instead of string.

* — Any value
, — Value list (e.g., 1,3,5)
- — Range (e.g., 1-5)
/ — Step (e.g., */15)
? — No specific value
L — Last (day of month/week)

Examples

0 0 * * * — Daily at midnight
*/15 * * * * — Every 15 minutes
0 9 * * 1-5 — Weekdays at 9am
0 0 1 * * — First of month
30 4 * * 0 — Sundays at 4:30am

How Cron Expressions Work

Cron expressions use 5 fields: minute, hour, day of month, month, and day of week
Each field can contain numbers, ranges (1-5), lists (1,3,5), steps (*/15), or wildcards (*)
Special characters: * (any), - (range), , (list), / (step), ? (no specific value)
The tool generates the expression and shows human-readable explanation
Preview next execution times to verify your schedule works correctly

Common Cron Examples

Daily at Midnight

0 0 * * * — Runs every day at 00:00. Perfect for daily backups or cleanup tasks.

Every 15 Minutes

*/15 * * * * — Runs every 15 minutes. Ideal for monitoring or polling tasks.

Weekdays at 9am

0 9 * * 1-5 — Runs Monday through Friday at 9:00 AM. Great for business hours tasks.

First Day of Month

0 0 1 * * — Runs at midnight on the 1st of every month. Perfect for monthly reports.

Frequently Asked Questions

What's the difference between 5-field and 6-field cron?

5-field cron (standard): minute hour day month weekday. 6-field cron (Quartz/extended): adds seconds as the first field. Most systems use 5-field format.

How do I schedule a task for weekdays only?

Use day of week field: 1-5 (Monday-Friday) or MON-FRI. Example: 0 9 * * 1-5 runs at 9am on weekdays.

What does */15 mean in cron?

*/15 means 'every 15 units'. In the minute field, */15 means every 15 minutes. In hours, */2 means every 2 hours.

Can cron handle timezones?

Cron runs in the server's local timezone. For UTC, set your server timezone to UTC or use tools that support timezone specification.

What happens during daylight saving time changes?

Cron schedules are based on system time. During DST transitions, tasks may run twice or be skipped depending on your system's timezone handling.

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