Hey Blue, I was reading the posts on your problem and I would probably tackle the problem the same way. As an academic exercise, regardless of whether the doctor finds it useful or not, the first thing you'd need to do would be to set ranges for the time schedules. Larger ranges (Say 4am to 5am) would be less specific, but tighter ranges (4:00am-4:05am) would probably not gather as many time points as you would want to gain an average. If you want an easy way to do this, I would probably set up a small PERL script to write an interface file from form data. I'd use a dropdown box to allow them to pick the time ranges and have each range assigned a numerical value that corresponds to the line in the array that the data is stored. (IE, line 1 is 4-4:30, line 2 is 4:30-5 etc. etc.) The PERL script would need to parse the data from the form, read the current data from the file into an array. Dump the new data from your form into the array, and rewrite the file. You then would have a file that had all of the data, categorized, by timepoint. Last step is to create a script that reads the array and averages values stored in the array. Hope that helps. - Hutch