Neethu, you must first understand that, as Partha has said, many threads do not live for more than three days due to different reasons. So, the primary action on our part should be to read and respond to new threads as far as possible. We have kept the bracket of ten days for threads to be responded to so that new threads do not go to the back pages without getting any responses.
Now coming to your point, the threads appearing in the index are as per date they have been posted and the date does not change irrespective of the date on which responses are posted. So, if you want to look through threads that have been posted within ten days, you may have to scroll through four or five of the index pages; it does not take much of your time. It may be easier for regulars but for those who are not that regular, I feel they should be ready to spare a few more minutes of their spare time to look for threads that might interest them. We already have a link for 'New Submissions' and adding any more features will only help in cluttering our pages. Anyway, your suggestion has been registered and will be considered as and when time and space permits.
'Knowing others is wisdom, knowing yourself is Enlightenment'- Lao Tzu