mac photos sort pictures by date taken
how do you sort the pictures in mac photos under the "all photos" list by the date the pictures were taken?
if i go to the view menu, the only semi-applicable choice says "Keep Sorted By Date Added." There's a check mark next to that option. The entire line, however, is greyed out so that it can't be selected and there are no other sorting options.
thanks!
MacBook Air, OS X Yosemite (10.10.3)