chage 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 her password. The chage command is restricted to the root user, except for the -l option, which may be used by an unprivileged user to determine when her password or account is due to expire.
With the -m option, the value of mindays is the minimum number of days between password changes. A value of zero for this field indicates that the user may change her password at any time.
With the -M option, the value of maxdays is the maximum number of days during which a password is valid. When maxdays plus lastday is less than the current day, the user will be required to change her password before being able to use her account. This occurance can be planned for in advance by use of the -W option, which provides the user with advance warning.
With the -d option, the value of lastday is the number of days since January 1st, 1970 when the password was last changed. The date may also be expressed in the format YYYY-MM-DD (or the format more commonly used in your area).
The -E option is used to set a date on which the user's account will no longer be accessible. The expiredate option is the number of days since January 1, 1970 on which the accounted is locked. The date may also be expressed in the format YYYY-MM-DD (or the format more commonly used in your area). A user whose account is locked must contact the system administrator before being able to use the system again.
The -I option is used to set the number of days of inactivity after a password has expired before the account is locked. A user whose account is locked must contact the system administrator before being able to use the system again. The inactive option is the number of days of inactivity. A value of 0 disables this feature.
The -W option is used to set the number of days of warning before a password change is required. The warndays option is the number of days prior to the password expiring that a user will be warned her password is about to expire.
If none of the options are selected, chage operates in an interactive fashion, prompting the user with the current values for all of the fields. Enter the new value to change the field, or leave the line blank to use the current value. The current value is displayed between a pair of [? marks.