Missing 24 hours of access logs.

When I check my access logs, there is always the last 24 hours of logs missing. The current logs always start at 0800 with the current date , but when I look at the archived log, the last 24 hours worth of information is not there. I literally have to wait 24 hours to see who was accessing my site last night. Why is that? Where is that data for those 24 hours and why can I not access it??? Do you think that data is something I can do without? Why do I have to wait 24 for hours to see who accessed my site? If the data isn't in awstats, or raw access logs or archives, where is it? I need to see this information for security purposes.