slingshotz

So is there any way to setup a trigger to trigger every 30 minutes to get around this problem? I can't seem to find a way to do this except triggering daily which is not enough. I'm looking at using hte CRON expression to do this but it's pretty confusing to me but does this look right as an expression to trigger every 10 minutes starting immediately? "0 0/10 * 1/1 * ? *"