It’s easy once you understand the terminology and process.
When a call is placed on hold, the hold timer begins. When the hold timer expires, the call is routed to the Recall destination. It rings there until the recall timer expires, then the call is routed to the Attendant station.
There are 3 timers, which are system-wide. That means you can’t have custom timers on a per-station basis. The Hold timer is self-explanatory. The Alternate Hold timer is used instead of the Hold timer, and is selected under station flags. The Recall timer was explained above.
The Alternate Hold timer just gives an option for a second hold timer. If you want the call to stay on hold and never recall, set the Alternate Hold timer to zero and enable the station flag.