In an Active Directory RBA integration, when setting the user data for the AccountExpires attribute you will need to convert your date into a Windows File Time format. If you try and set your date attribute with a string "YYYY-MM-DD" or "MM/DD/YYYY" you will get this error: "The attribute syntax specified to the directory service is invalid.To overcome this issue I had to create a Powershell Activity, that runs before my AD Account Create, and runs a Powershell command to get the date in Windows File Time format. The command is this:

(Get-Date 12/25/2012).ToFileTime() **Merry Christmas**

You can use the activity.output to get a response similar to this:

129067992000000000

This is the value you set in the userdata for attributes such as AccountExpires.