hi
i need to know how to set user login times that is for eg
a user USER1 has login access only between 10 am to 4 pm,
which configuration file i need to modify, send me suggesstions
at alagesh146@gmail.com

In order to lock and unlock a user's periodically, make two 'cron'-directories:
# mkdir /etc/cron.lockuser
# echo "/usr/sbin/usermod -L USER1" > /etc/cron.lockuser/lockuser1
# chmod a+x /etc/cron.lockuser/lockuser1
# mkdir /etc/cron.unlockuser
# echo "/usr/sbin/usermod -U USER1" > /etc/cron.unlockuser/unlockuser1
# chmod a+x /etc/cron.unlockuser/unlockuser1

end then edit the file /etc/crontab with two extra lines:

00 10 * * * root run-parts /etc/cron.unlockuser
00 16 * * * root run-parts /etc/cron.lockuser

This will enable the password for USER1 from 10.00h until 16.00h. If the user uses another type of authentication to log in, you may want to change the lockuser1 and unlockuser1 files in another way:

# echo "/usr/bin/chsh -s /sbin/nologin USER1" > /etc/cron.lockuser/lockuser1
# chmod a+x /etc/cron.lockuser/lockuser1
# echo "/usr/bin/chsh -s /bin/bash USER1" > /etc/cron.unlockuser/unlockuser1
# chmod a+x /etc/cron.unlockuser/unlockuser1

this worked for me
regards

How about PAM? As in /etc/security/time.conf?
And no we don't do email, that's just too lazy of you.

I know some sysadmins that just change the loginshell to "nologon" during times said user is not supposed to be active, of course taking account of the original shell type so they can be restored correctly.