Build cron expressions visually — with a live schedule preview.
Paste any cron expression, pick a start point, and preview upcoming runs.
A cron job schedule is defined by a text string of 5 or 6 fields. Each field represents a unit of time and dictates when the task runs. Use our visual builder tabs to configure these schedules instantly: configure minute intervals, hourly repetitions, daily routines, or weekly tasks.
| Field | Required | Allowed Values | Special Characters |
|---|---|---|---|
| Seconds | No (Quartz only) | 0–59 | * , - / |
| Minutes | Yes | 0–59 | * , - / |
| Hours | Yes | 0–23 | * , - / |
| Day of Month | Yes | 1–31 | * , - / ? L W |
| Month | Yes | 1–12 or JAN–DEC | * , - / |
| Day of Week | Yes | 1–7 or SUN–SAT (Quartz) / 0–6 (Unix) | * , - / ? L # |
A cron expression is a string composed of fields representing a schedule. The cron parser reads these fields to trigger scripts or tasks at specific intervals automatically.
Unix crontab has 5 fields and operates at minute granularity. Quartz is a Java-based scheduler that adds a 6th field for seconds and supports advanced logic like targeting the last day of the month (L) or the Nth weekday (e.g. 2nd Monday).
To run every 5 minutes, use the expression */5 * * * * for Unix crontab, or 0 */5 * * * ? for Quartz schedules. Selecting the Minutes tab in CronJob generates this for you automatically.
In a cron expression, the asterisk (*) acts as a wildcard symbol meaning "every" or "all values". For example, placing an asterisk in the Hours field means the task will execute every hour.
The question mark (?) wildcard is used in Quartz cron expressions to specify "no specific value". It is required in either the Day-of-Month or Day-of-Week field to denote that the constraint is not active for that specific day metric.