There are a bunch of systems out there for time clock. Instead of a time card / badge swipe, I would recommend a biometric/finger print system. Eliminates "buddy punch" or your staff coming to you because they lost their card.
We already have our Prop & Costume Manager software for signing out costumes to actors and in time we will integrate a staff module into our POS system. This will link staff details with sales data allowing haunters to review how efficient the event is running. Sales vs. payroll. Plus it would keep all staff details in one system.
Good luck on your hunt!