Cron expression to run every N minutes -

i need build cron expression run job every 10 minutes after user click on start button.

i'm trying like:

0 42/10 * * * ? * 

and 42/10 user click start @ hh:42 (example: 18h42). next schedule like:

1.  friday, march 20, 2015 6:42 pm 2.  friday, march 20, 2015 6:52 pm 3.  friday, march 20, 2015 7:42 pm 4.  friday, march 20, 2015 7:52 pm 5.  friday, march 20, 2015 8:42 pm 

the problem after second execution, job waits hour perform next execution. how can build cron expression starts , after still running after n minutes?

thank in advance.

i think format wrong. order of fields is:

1. minute
2. hour
3. day of month
4. month
5. day of week
6. command

so in example, minute 0, , hour invalid (hour must in range 0-23). i'm guessing cron ignoring incorrect hour, , running on minute 0 of every hour.

however, if did want run every n minutes, use format (where n less 60):

0/n * * * * /bin/echo "your command here" 

however, keep in mind /n repeats command every n minutes within current hour. so, if have 0/33 in crontab command run at:

• 00:00
• 00:33
• 01:00
• 01:33

not at:

• 00:00
• 00:33
• 01:06
• 01:39