LDAP: accountexpires attribute values
Account expiration in Active Directory is represented by 2 values, accountExpires (ldap attribute) and AccountExpirationDate (ADSI method). The latter does an automatic conversion of the accountExpires attribute for you. The format of accountExpires is integer8 and has to be converted to a readable date/time. The number you see in AD is the number of 100-nanosecond intervals since 12:00 AM January 1, 1601. Possible default values:
9223372036854775807: Represents “Never” if value has never been set before
0: Represents “Never” if value has been reset after having another value