I have a query regarding password policy in Linux


There are two things in Password Expiration Policy in Linux which is making me bit confused. That is :

Maximum number of days between password change


Minimum number of days between password change

First one I understood that Suppose I set Maximum Number of days between password change as 30 days means the Password will be active for next 30 days and we have change the password within 30 days.

But I dont understand What is the use of Minimum number of days between password change.

Any Suggestions



Here Min no.of days related to password change

i’ll explain you in brief if you set MIN_DAYS value to zero then that user could change his/her password at any point of time.

If you set any value to MIN_DAYS then the user has to wait min_days for password change.

If user tries to reset password before minimum_days set, he/she will get error as listed below.

$ passwd
Changing password for test.
(current) UNIX password: 
You must wait longer to change your password
passwd: Authentication token manipulation error
passwd: password unchanged