Thanks for your reply. I have taken your advice and am reading the access logs from the bottom up. But I am also going to write a script which can parse a given time interval from the access logs. And I believe a binary search is the perfect solution. For my own benefit I'm going to roll my own binary search for this script. I'll post it here when it's completed.
Re^2: Using binary search to get the last 15 minutes of httpd access log
Replies are listed 'Best First'.