Need to disable scheduler completely by safety reassons.
Is it possible?
From HDP 2.6.5 onwards,
By default user will not see scheduler, as it is disabled by default.
If a user wants to enable scheduler, you will need to add a "zeppelin.notebook.cron.enable" with value "true" under custom Zeppelin site in Zeppelin settings from Ambari.
If you are using version 2.6.4 OR less create a support ticket OR upgrade it.