Thanks to a bunch of issues with repeating events, I went and did a manual reset on the events calendar. Pretty much deleted every repeating event and recreated them from scratch. One of the problems dealt with how repeating events will repurpose existing nodes instead of creating new ones, which screwed up all the URL aliases generated by pathauto. The other problem is with Drupal's handling of time zones.

The time/date settings for Drupal allow a site administrator to set an absolute difference from Zulu, but there is no allowance for DST. A more proper system would allow time zones to be set by name, with tracking of DST (including its start and end, all the more important now). The event module does allow event nodes to have a time zone set in this way, though.

If you check out the iCal feed for events, you'll notice that the repeating events are all off by an hour. This could be a problem with Drupal itself or it could be an issue with the repeating events module; I don't know. But I'm quite certain that it ultimately stems from the weak and simple way time zones are handled in Drupal.