Overview#Password Expired is a LDAP Result Code from Common Edirectory Bind Errors that indicates the EDirectory Password Expiration.
For EDirectory the normal case when the password policy has been set for the password to expire after an administratively set number of days.
The PasswordExpirationTime attribute is calculated by adding the password expiration interval to the time that the password changed. It is calculated when the password is set and then is recalculated during login if the password interval has been changed. This allows the administrator to set a password to expire at some pre-determined time.
Additional information is available on the Password Expired mechanism in Password Expiration