It's not abnormal to see time stamps like that with print publications - they often publish to the web in advance of the print edition coming out, but it makes sense to use the print edition as the 'reference' edition when it comes to dating articles.

Haha.

Just noticed that part.

From Wikipedia:

  Started as a weekly in 1925, the magazine is now published
  47 times annually, with five of these issues covering two-
  week spans.

Perhaps that's when its slated to appear in the print edition?