[squid-users] Authentication

Hi everyone,
 
I have Linux box(Red hat 7.3) running squid 2.4 stable7.At present I have
configured IP based restriction to my users.Now I want to configure like,all
user will have 1 hour internet access during office hour(or say per
day).User will use internet as and when they require but only for 1
hour(cumulative).
So is it possible with Squid and which authentication method is right for
me?
 
Does anyone have a better idea on how this can be done? Your inputs are
deeply appreciated. Thanks everyone!
 
Ritesh