Play framework scheduled jobs and crontab

In the play framework, there is a Job class that can execute a certain process periodically, and the interval is written in the parentheses of @On () as follows.

import play.jobs.Job;
import play.jobs.On;

@On("*/2****")
public class xxxxx extends Job<Void>

You can use the crontab notation to set the time interval, and the following sites are very easy to understand.

https://crontab.guru/#/15_*_

• Note that a space is required between the asterisks (*) behind.

crontab Koand I knew it for the first time, but it's really convenient