[CentOS] set up login.defs but password still not expire?

We have Centos 5.8 on LInux server.I setup /etc/login.defs following: PASS_MAX_DAYS   3 PASS_MIN_DAYS   0 PASS_MIN_LEN    8 PASS_WARN_AGE   1

after that I chack user password policy and it show:# chage -l user1 Last password change                                    : Jun 29, 2015 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

anyone know why?   I did reboot server still same.