I think keywords and collections are preferable tools to organize images this way. For example, make a collection called Weddings. Then inside that, you have child collections. Each child collection corresponds to a single wedding. So if you want to find all the weddings for 2007, you just click on the Weddings collection in the list of collections, then go to Find and restrict your viewing to "this year" (i.e., 2007). Voila -- only the wedding images from 2007 show up. And if you're interested in just seeing the images from a particular wedding, click on the specific child collection.