You can't and there is no plugin or product available for this. You can only specifiy the "Day of the Week", the "Day of the Month" (disables "Day of the Week"), "at the Xth Hour of the Day" and up to 6 "each Xth Minute".
If you need to run a cron job every 4 hours, then you have to use the Cron (Unix/Linux Systems) or Scheduled Tasks (Windows Systems) of the underlying Operating System.
|