How to sort All Enrolled Users by date added

The URL of manager/people/all points us to the pages/manager to find the handler. Within the PeopleHandler, we find the definition of the sort:

It is passed to the Data Access Object here (for role-specific searches):

Or here (for searches not limited by a role):

The field that you are interested in is probably users.date_registered:

If you wanted to display that on the screen for sorting, note that the Handler calls the manager/people/enrollment.tpl:

See that template here: