PAM & /etc/security/time.conf

Question

I need to change the permissions access based on time in Ubuntu. I have a user called "miguel" and I want miguel not to gain access on Saturdays from 00:00 to 19:00 hours.

I read in web pages that this is simple:

1. I write this line in /etc/pam.d/login:

   account required pam_time.so
   

2. I write this line in /etc/security/time.conf:

   login;*;miguel;!Sa0000-1900
   

I saved this files with the changes.

But this not working!! I need help!! Thanks a lot!!