Cron Expression Builder

Build, validate, and understand cron expressions. Live human-readable description, next 5 run times, 12 presets, and a field-by-field editor. Type directly or click a preset.

Field reference

The 5 fields of a standard Unix cron expression

Field	Range	Examples
Minute	0–59	0 (at minute 0) · */5 (every 5 min) · 15,45 (at :15 and :45)
Hour	0–23	9 (9am) · 0,12 (midnight & noon) · */6 (every 6h)
Day	1–31	1 (1st) · L (last) · * (every day)
Month	1–12	* (every) · 1-6 (Jan–Jun) · JAN,JUL
Weekday	0–6	1-5 (Mon–Fri) · 0,6 (weekends) · MON,WED,FRI

Special characters

*Wildcard

Matches every value in the field. * in the minute field means every minute.

*/nStep

Every n-th value. */5 in minutes means every 5 minutes (0, 5, 10…).

a-bRange

Every value from a to b inclusive. 9-17 in hours means 9am through 5pm.

a,bList

Specific values. 0,30 in minutes means at :00 and :30.

LLast

Last day of the month. Only valid in the day-of-month field.

?No specific

No specific value. Used by some implementations (Quartz) to avoid conflicts between day-of-month and day-of-week.

Frequently asked questions

What is a cron expression?

A cron expression is a string of 5 (or 6) space-separated fields that describe a schedule. The fields represent minute, hour, day-of-month, month, and day-of-week. The cron daemon reads these expressions and runs the associated command at every matching time.

What does * mean in a cron field?

An asterisk (*) means 'every valid value'. In the minute field it means every minute (0–59). In the hour field it means every hour (0–23). It's the most common value when you don't want to restrict a particular unit.

What is the difference between day-of-month and day-of-week?

Day-of-month (field 3) triggers on a specific calendar date, like the 15th or the last day of the month. Day-of-week (field 5) triggers on a day name regardless of the date, like every Monday. When both are specified as non-asterisk values, most implementations trigger if either condition matches.

Does this support seconds (6-field cron)?

This tool uses the standard 5-field Unix cron format (minute, hour, day, month, weekday). Some platforms like Spring Boot, AWS EventBridge, and Quartz use a 6-field format with a leading seconds field. Check your platform's documentation — the fields shift by one position.

How do I run a job every weekday at 9am?

Use 0 9 * * 1-5 — minute 0, hour 9, any day of month, any month, Monday through Friday (1–5). The presets panel includes this as a one-click option.

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