# CRON Trigger
# Description
The CRON trigger runs a job periodically according to its cron expression. Just like the UNIX cron daemon does.
A CRON expression consists of six fields:
second, minute, hour, day, month, weekday
Month and weekday names can be given as the first three letters of the English names.
The following special characters can be used in a CRON expression:
| character | means | explanation | example |
|---|---|---|---|
| * | all | the event should happen for every time unit | "*" in the 'minute' field means "for every minute" |
| ? | any | denotes in the 'day-of-month' and 'day-of-week' fields the arbitrary value | "?" in the 'day-of-week' field indicates that the event should occur no matter the actual week day |
| - | range | determines a value range | "20-23" in the 'minute' field means "run at minute 20, 21, 22, 23" |
| , | values | specify multiple values | "2,5,11" in the 'hour' field means "run at hour 2, 5 and 11" |
| / | incremental | specify incremental values | "5/15" in the 'seconds' field means "the seconds 5, 20, 35 and 50" |
# Examples
| CRON expression | Description |
|---|---|
| 0 0 * * * * | The top of every hour of every day. |
| */30 * * * * * | Every thirty seconds. |
| 0 */15 * * * * | Once every fifteen minutes. |
| 0 0 8,10 * * * | 8 and 10o'clock of every day. |
| 0 0/30 8-10 * * * | 8:00,8:30,9:00,9:30and 10o'clock every day. |
| 0 0 9-17 * * MON-FRI | On the hour nine-to-five weekdays. |
| 0 0 0 25 12 ? | Every Christmas Day at midnight. |
# Parameters
The component can be configured by the following parameters:
| Parameter | Description |
|---|---|
| Cron Expression | The CRON expression that is used to trigger the job. |