The "Timer" Column in Show Pro is an optional field to set up automatic timers and/or stopwatch.
Setting a timer for a cue is simple. Just hover over the timer cell for the particular cue and click on the "+" icon. You can set the hours, minutes and seconds of the timer in the pop up window.
This is also where you can attach a Stopwatch trigger. A clock symbol in the cue Timer column will indicate if a Stopwatch is attached
Then in Rehearsal Mode and Show Mode, the timer countdown clock is displayed in the "Timer" box.
The same countdown clock is displayed on any connected iPad in the top designated as "Timer".
While in RM or SM triggering the timer countdown clock is automatic; once you click "GO" or hit the space bar to advance the cue to the "Current Cue" position the timer will automatically display and begin to count down.
If you would like the timer to stop at zero or continue to count up after it reaches zero, change the settings in the drop down menu under: Format - General Settings - Countdown Behavior