This is a simple hack I made over the weekend. I wanted to play around with the recently released API of the German weekly newspaper Die ZEIT, and at about the same time Randall Munroe published this comic. So as a regular reader of xkcd, I thought I could figure out what his "Calendar of Meaningful Dates" looked like in Germany. What this hack does: It searches the ZEIT API for all dates and counts the results. The dates are displayed according to the number of search results.
The calendar is continually being updated by a background cronjob, but as of now it turns out that the first and last days of each month were mentioned quite often. Other remarkable dates are
On mouseover, a tooltip over the days displays the number of articles found for the respective date. If you click on this tooltip, you will be redirected to the corresponding search results on ZEIT ONLINE (don't ask me why the number of hits differs).