Don't know if you're still looking for an answer, but here's what I did (yes, it's a workaround, but it works!):  Set a new Memorized Transaction group.  Lists > Memorized Transactions.  Create a new Group--I named mine, "Run Payroll 15th & 31st."  Select "Add to My Reminders List."  Set How Often (weekly, bi-weekly, semi-monthly, etc.), and set Next Date--this should be the first date you want to be reminded. 

This only serves as a reminder on your Reminders list, and you should make sure your reminders are set to display when you open Quickbooks.  You will still need to manually open Payroll and run your Direct Deposits, but at least the reminder to do so will show up in your Reminders list.