The writing method of n/m in the cron expression has always been thought that it must be triggered from n, and then triggered again every time m is increased. Later, it was found that this is not the case. As long as the conditions of n, n+m, n+2m... are met, it will trigger without waiting for n.
For example, 0/1 * * * * ? This is executed every 1 second, because any second is eligible
0 0/5 * * * ? This is executed every 5 minutes, that is, it will be executed as long as it is 0,5,10,15... minutes