Time is important. The date stored along with a photo determines how iPhoto sorts the photo. Accurate dates also simplify searching and organizing your library.
All digital cameras store date and time information along with the image (see the sidebar on page 141). But what if your camera’s clock is off? Maybe you forgot to adjust its time zone when you flew to Hawaii.
Or maybe you’ve scanned some old family photos and you want their dates to reflect when they were taken, not scanned. That Aunt Mary photo is from 1960, not 2012.
Time travel is easy in iPhoto. You can edit the date of an event, a selection of images, or just one photo: select the items you want to change and choose Photos > Adjust Date and Time.