When someone logs in for the first time on a given day, is it possible for them to have the same auth number each time they log in thereafter for the period of time specified in the .cfg?

eg: name.96113778081401 is first assigned.
My $auth_time = 21600; # 6 hours
If I log in again during the following 6 hours I get the same
name.96113778081401
6 hours after the first login though the file id deleted and then the next time I am assigned a new number.

Make sense?
As always.....Thanks!
Adam