Logstash - Scheduler (rufus scheduler)

I am trying to schedule logstash run for every 5 mins every day (full week) expect during certain time intervals in a day (between 10:00 AM - 10:30 AM). I know I can use the cron syntax for the job "schedule => "*/5 * * * *"" and that should run every 5 mins. But how can add this exception to it (not to run between 10:00 AM - 10:30 AM).
I know that rufus is based on cron syntax and I tried few ways but that didn't worked for me.
Any help here folks will be appreciated.