field showing elapsed time during survey, but not tracked in database

[MelodeeBassett]

Users have 8.5 hours to unload a train.  They would like a "stop watch" field that displays the time elapsed since the placement time was entered.  The placement time is the first entry they make in the survey.  The new field is for display purposes only and not part of the existing features et or related tables.  It is only for users to know how much time they have left to unload before demurrage fines start.

Is there a way to do this?

[DougBrowning]

Here is my calc for it.  (I think I posted it recently as well)

round(int(now() - ${StartedForm}) div (1000*60),1)

To keep it out of the feature service just set the bind::esri:fieldType to null.