about the space -- its server and os dependant ( our windows servers start to have issues around 2 gb of files in a folder) so splitting the data up between folders reduces the strain
i create them on the fly....first I check for the year folder, based on server date, then create if its not there. I then check for the week folder in that year folder, and create it if its not there...i am using asp for this not php, so the code i could provide won't be as helpful