Updated my Lenovo Yoga 11s to 8.1. The photo gallery no longer has a sort by date option, and I'm surprised there isn't any hue and cry about it online.
Previously after you open the gallery, you select your root folder, slide down from top of screen, and there's a sort by date option (among the other options). When sorted by date, the gallery will show you thumbnails organized by month (Oct 2013, Sept 2013, Aug 2013, etc), and tapping the thumbnail shows all photos taken during that month. Now all there is are: select all, new folder, import, slide show.