The problem with the file system and other ways mentioned, is that pictures have meta data which stores the 'date photo taken' - and it is not always the date modified (if you removed redeye or something beforehand).

I had to write a tool which loads the date modified so that I can sort the stuff and do a basic filter (text with a # which inserts the numbers for the selection). I've never seen another tool out there which does it, and it's pretty easy to make. I'd suggest going that route if you have a lot of photos and really want the date to be accurate.