If you’ve ever forgotten to set your camera’s clock or adjust the time for daylight savings time, you probably know what a nuisance it is to manually correct your photo’s timestamps. Joe Maller addressed this problem by writing a few AppleScripts that allow you to shift and reset dates and times for album photos in iPhoto. This could save you a lot of time if you need to correct the dates on several photos at once. After you’ve installed the tools, you just select images within iPhoto and run the script from the menu bar.
Joe’s iPhoto AppleScripts –Link.