account policies and ldap attributes related?

[Andreas]

What is the relationship between the following account policies
and similar LDAP entries in samba-3.0.2a:

pdbedit -P:					ldap attrbiutes
(btw, what's the			(uses epoch as far as I can tell)
unit of measurement
here?)

minimum password age		sambaPwdCanChange
maximum password age		sambaPwdMustChange
disconnect time				sambaKickOffTime, sambaLogoffTime

On a more general note, when do account policies apply? Is it some sort
of "default" for new accounts? Does it apply to all user accounts?