This chart is rather mind blowing. Such attention to detail!

Reddit comments:

http://reddit.com/r/xkcd/comments/2x2wov/xkcd_1491_stories_of_the_past_and_future/

Reddit comment:

This one's a miss. The labeling is sloppy, with the first date appearing to be 2000 AD until you notice it's a bidirectional scale and the second date is labeled BCE. The Still Possible / Obsolete legend looks like the titles straddling the "stories set in 2015" line. The vertical scale doesn't make clear whether those years are relative to now, or relative to date of publication. I didn't even notice the legend for the lower line until I started writing this comment.

This ought to be publication date vs. setting date, linear or log as the data makes appropriate, with one straight line marking 2015 ("obsolete"). At the very least, publication date should be logarithmic in one direction - relative to now, as the "years in the future / past" are relative to now.

More explanation: http://www.explainxkcd.com/wiki/index.php/1491