Stax

Cron Expression Builder

Build and validate cron expressions visually — minute, hour, day, month, weekday fields with human-readable preview.

0–59
0–23
1–31
1–12
0=Sun, 6=Sat
CRON EXPRESSION
0 9 * * 1

Every Monday, at 9:00 AM

FieldValueMeaning
Minute00–59
Hour90–23
Day of month*1–31
Month*1–12
Day of week10 = Sun, 6 = Sat
COMMON PRESETS

How cron expressions work

A cron expression has five fields, read left to right: minute · hour · day-of-month · month · day-of-week. Each field accepts a number, a wildcard (*), a range (1-5), a list (1,3,5), or a step (*/15). Combine them to express nearly any recurring schedule without writing a single line of code.

How to build a cron expression

  1. Fill in each of the five fields — leave * for “every”.
  2. Watch the assembled expression and human-readable preview update live.
  3. Use the preset buttons to start from a common schedule.
  4. Click Copy to copy the expression to your clipboard.
  5. Paste into your cron scheduler (crontab, GitHub Actions, AWS EventBridge, etc.).

Common cron patterns

  • * * * * * — every minute
  • 0 * * * * — top of every hour
  • 0 0 * * * — daily at midnight
  • 0 9 * * 1-5 — every weekday at 9:00 AM
  • 0 0 1 * * — first of every month at midnight
  • */15 * * * * — every 15 minutes
  • 0 9,18 * * * — 9 AM and 6 PM every day
  • 0 0 * * 0 — every Sunday at midnight

Where cron expressions are used

Cron expressions originated in Unix but are now standard across the industry. Linux/macOS crontab is the classic use case. Cloud platforms use the same 5-field format: AWS EventBridge(with a slightly extended syntax), GCP Cloud Scheduler,Azure Logic Apps, and Kubernetes CronJobs. CI/CD systems like GitHub Actions use cron syntax for scheduled workflow triggers.

よくある質問

What is a cron expression?
A cron expression is a string of five space-separated fields that defines a recurring schedule for automated tasks. It is used in Unix/Linux cron jobs, CI/CD pipelines (GitHub Actions, GitLab CI), and cloud schedulers (AWS EventBridge, GCP Cloud Scheduler, Kubernetes CronJobs) to trigger work at precise times without manual intervention.
What does each field in a cron expression mean?
The five fields are: Minute (0–59), Hour (0–23), Day of Month (1–31), Month (1–12), and Day of Week (0–6, where 0 = Sunday). Example: '0 9 * * 1' means 'at 9:00 AM every Monday'. An asterisk (*) means 'every valid value for that field'.
What do *, /, -, and , mean in cron syntax?
* means 'every' (e.g., * in the minute field = every minute). / means 'step' (*/15 = every 15 units). - defines a range (1-5 in day-of-week = Monday through Friday). , separates a list of values (1,3,5 = Monday, Wednesday, Friday). These can be combined: 1-5/2 means every 2nd day from Monday to Friday.
How do I run a job every 5 minutes?
Set the Minute field to */5 and leave all other fields as *. The full expression is '*/5 * * * *'. This fires at :00, :05, :10, :15, and so on throughout every hour of every day.
What is the difference between Day of Month and Day of Week?
Day of Month (field 3) targets specific calendar dates — e.g., 1 means the 1st of each month. Day of Week (field 5) targets specific weekdays — e.g., 1 means every Monday. When both are non-asterisk, most cron implementations fire when either condition is met (OR logic), not only when both match.
Does this tool run the job or just build the expression?
It only builds the expression string. No jobs are executed. Copy the expression and paste it into your cron scheduler — your Linux crontab, GitHub Actions schedule trigger, AWS EventBridge rule, or whichever platform you use.

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