I'm trying to set up a rule in the Command Transform Policy set that,
when a user account is disabled in AD, will add an attribute to the
account in the vault with the date on which the account was disabled.

The test condition is:

"if operation attribute "Login Disabled" changing to 'true'".

I created a custom attribute 'DirXML-AdDisabledDate' under the auxiliary
class 'DirXML-EmployeeAux' and set the action to be:

"add destination attribute value ("DirXML-AdDisabledDate", class
name="DirXML-EmployeeAux", Time (format="MM/dd/yy, hh:mm") ) ".

I know the test condition is working because I configured a second action:

"add destination attribute value ("Description", class name="User", "AD
account disabled on " + Time (format="MM/dd/yy", lang="en-US") ) ".

This works as expected. What am I missing with the custom attribute?