You need to use the chage command. It can display password expiry information as well as changes the number of days between password changes and the date of the last password change. This information is used by the system to determine when a user must change his/her password.

# chage -l bob
Last password change					: Apr 14, 2014
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