iOS is no stranger to Daylight Saving Times bugs. It could actually be considered a recurring things as we've seen several occurrences of Apple's operating system not properly adjusting to time changes in the past, most notably back in 2010 and twice in 2011.
After all this time, you'd think Apple would have figured out how to properly adjust such a basic feature, but apparently they haven't. Some French users are reporting today that although the time has adjusted correctly to the country's DST change, there is still a little bug visible in the Calendar app...