A friend using Apple's powerful Aperture photo management application asked me how to sort photos into date ranges, such as an entire year, a calendar month, or by day. Here's how to do it with Aperture's Smart Album feature.
First, create the Smart Album by ctrl-clicking on the Library folder and choosing "New Smart" then "Album". The same thing is available from the File menu.
A grey-black semi-transparent Heads-Up Display or "HUD" will appear, and from the HUD's plus drop down in its upper right corner, select "date". A Date line is added to the HUD, and you can choose "Image Date" "Is In The Range" and enter your date range in the boxes. Note also the "Calendar" selector, which seems only to do a single day.
Notice a couple more things about the HUD. Each criteria line has a checkbox which serves to enable or disable the criteria. There is a "Include if" line with a dropdown, from which you can choose "Any" or "All" from, and whether to check for matches or no matches. This covers the selection logic, and acts upon all the selected criteria below. You can also choose just to filter if the photo was a stack pick, using the checkbox for that in the lower left of the HUD.
When you are done entering criteria, click the X in the HUD's upper left corner to close it. You can reopen the HUD by clicking on the little magnifying glass to the right of the Smart Album itself, to reopen the HUD. I'm using Aperture 2.1.1 at the time of this writing so your mileage may vary.