[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.