Today we noticed a scheduled build was launched one hour too early by Team Foundation Server. After figuring out what Microsoft meant with "Roman Daylight Time" and wether we are in "UTC+1" or "UTC+2" or "UTC+1+1 Daylight Savings Time" it turned out we configured our systems correctly, but a bug was introduced in TFS 2013 Update 2.
The good news is that Microsoft promises the bug is fixed TFS 2013 Update 3, for which there is currently a Release Candidate.
So if you are running TFS 2013 Update 2 it is worth checking out if your scheduled builds are actually running at the time you expect them to. :-)