I wanted to enable time limit for some users so they are able to use FTP server only during working time.
For RH based systems with Vsftpd
Open /etc/security/time.conf and add
| vsftpd;*;SOME_USER;Al0800-1600 | 
to the end.
Then open /etc/pam.d/vsftpd and add
| account required pam_time.so | 
as the first line in account section so the file looks a like:
| #%PAM-1.0 session optional pam_keyinit.so force revoke auth required pam_listfile.so item=user sense=deny file=/etc/vsftpd/ftpusers onerr=succeed auth required pam_shells.so auth include password-auth account required pam_time.so account include password-auth session required pam_loginuid.so session include password-auth | 
Save the changes and try to login via ftp. In case you want to disable SSH, you should do the same:
Add
| account required pam_time.so | 
inside /etc/pam.d/sshd and
| sshd;*;SOME_USER;Al0800-1600 | 
inside /etc/security/time.conf file.
