When a user logs on, the system will verify the user's name and password. Additionally, the system will also check whether he or she is allowed to log on at this particular point in time, by checking the personal start date and end date. These dates are compared to the system date (of the server).

If a user's start date is later than the system date on which he or she tries to log on, the logging on process is stopped. The same principle applies to a situation where the user's end date is earlier than the system date on which he or she tries to log on.