Password aging is a mechanism that allows the system to enforce a
certain lifetime for passwords. While this may be moderately
inconvenient for users, it ensures that passwords are changed
occasionally, which is a good security practice. Most Linux
distributions do not enable password aging by default, but it's very
easy to enable.

By editing /etc/login.defs, you can specify a few parameters to set the default settings for password aging:

PASS_MAX_DAYS   99999

PASS_MIN_DAYS   0

PASS_WARN_AGE   7

change These values as you want. change 9999 to 7 to enforce all users to change their password every 7 days.

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