You aren't looking for Events in this situation, actually: those are how photos are organized as they're imported into iPhoto and should be named based on the specific events that they describe, as in "Day at Malibu Beach" or "Grandma's Birthday" or "Cousin Joey gets Married" or whatever.

Each picture has its date and time detailed and stored, however, because just about every digital camera in the world now records what's called EXIF information, that includes the date and time, but also includes ISO settings, shutter speed, lens focal length, and, if you have a GPS in your camera, latitude and longitude too, so you can map the photos by location later (a super-cool feature of Apple's iPhoto, of course!)

Instead, what you want to do is create an Album, but not just any album, specifically you want to create a Smart Album, which is designed for just this purpose.

In fact, I've created a lot of Smart Albums because it lets me, for example, pull out just the photos that have all three of my kids tagged with the Faces capability. Super helpful, especially given that I have just shy of 5,000 pictures in my iPhoto library.

To get started, go to File --> New Smart Album:

Once you do that, you'll see the basic Smart Album creation window:

Click on "Album", however, and you'll see that there are a LOT of different criteria you can specify to get exactly the selection you seek:

In this situation, you want to choose "Date", so select that. Now you'll see the conditional options within that category:

Since you want to specify a range, choose that and you'll see that the date itself now splits into two. Specify the first day of January to the last day of December and you'll have a year range:

That's all there is to it: just click "OK". You've now created a new Smart Album that will show up on the left navigation of iPhoto and will only contain the photos in the iPhoto library that match the date range you've specified.

That wasn't too hard, was it?