I am culling on my new macbook pro. I would like to update the image time for an entire set of images, since I am a wedding photographer. To do this on my iMac, I just select an image first and then select all of the images from that camera. I can then change the time of the selected image and then adjust all of the other images to match.
On my macbook pro, I have the option to change all when they are all selected, but only the super selected image (I know, that's not the right term...but the image I am working on) will adjust.