Gaurav.. that link is not having solution for that ! anyways.
allowing certain websites for a particular user in particular time is rather a confusing acl. Lets try..
First of all we have to define user based on IP addres, secondly we have to define websites to allow, thirdly we have to define time acl and lastly make a rule to comply all !
for doing first option ie defining acl for particular user
acl user1 src 192.168.1.15
or for the group of users say 3
acl grp1 src 192.168.0.4 192.168.0.5 192.168.0.6
Now secondly we have to make a website list which we want to allow, we will put them in a text file. To do so create a file and put website which you want allow in that 1 url per line, say we create a file allowedsite.txt and want to allow only 5 websites.
The content of file allowedsite.txt :
yahoo.com
linuxsolved.com
google.com
tldp.org
linux.com
Now we have to create acl for this file
acl allowed_websites dstdomain "/usr/local/squid/etc/allowedsite.txt"
Thirdly we have to create time acl when the user are allowed to do.. say they are allowed to do internet from 12:00 pm to 4:00 pm.
acl NOON time 12:00-16:00
Lastly we have to create acl when the particular user is accessing the internet at right time and only opening the allowed site.
http_access allow user1 allowed_websites NOON
http_access deny user1
http_access deny !allowed_websites
Well this code took me time to make but still you have to do testing and hope you got the idea how these stuff works. Still in confusion then please ask.