Hello and Welcome to LinuxQuestions,
Have a look at the man page for chage.
It will exactly tell you what you need to know.
chage -l <username>
will give you output like this:
Last password change : Mar 24, 2011
Password expires : never
Password inactive : never
Account expires : never
Minimum number of days between password change : 0
Maximum number of days between password change : 99999
Number of days of warning before password expires : 7
depending on your settings.