[Samba] samba-ldap and password expiration

[Jérôme Tournier]

Hello every body,
i am using samba (2.2.8a) with ldap support. In the samba.schema,
there are special attributes relatives to the user passord:
pwdMustChange, pwdCanChange, kickoffTime, logoffTime, logonTime and
pwdLastSet.
All the samba's documentations i can found described those attributes
as "currently unused", execpt the last one that represent the time
modification since 1970.
But what do the others attributes are for ? Can they be used and
how ?
For example, i found that pwdMustChange can be used to force user to
change his password. It seems that if i set pwdMustChange to epoch
time+20, the user will have to change his password in 20s. And again
in 20s ... So can i force a user to change his password in n secondes,
but more later ?
Thanks a lot
-- 
Jérôme