Simon Willison’s Weblog

Calendars and crawlers

Douglas Bowman has been having some amusing problems with robots and his calendar. The calendar, visible on every page of the site, automatically adds a “next month” and “previous month” link to allow surfers to browser through the archive in both directions. Unfortunately, Doug ommitted the logic to stop showing a “previous month” link when there were no earlier entries. An enterprising crawler started following the links, and didn’t stop until it had reached 1542!

I’ve written a few dynamic calendars in the past and I’m pretty sure at least one of them was susceptible to this kind of bug. Definitely one to watch out for.