true contradictions and daylight savings time

Are there true contradictions?    Via reddit, I saw the following, which seems like it might be a list of decent candidates for true contradictions -- and these candidates don't seem at first glance to fall into any of the existing categories of supposed true contradiction. (A relatively accessible list of proposed candidates can be found here.)

After thinking about it a little, I think these are probably not good candidates for true contradictions: rather, it looks like 'Sunday November 3rd, 2012 at 1:30AM' is ambiguous.  And it is not a true contradiction when 'Maria was a philosophy major' is true and 'Maria was not a philosophy major' is also true, if there are two different people named 'Maria' (and the first majored in philosophy but the second didn't).

Or is there something special about time, that makes these daylight savings cases different from garden-variety ambiguity cases (like 'Maria')?  Am I missing something?


 (For any readers wondering 'Why does it matter whether there are true contradictions?': It is a theorem of classical logic that everything follows from a contradiction.  Many people have found this counterintuitive and want to reject it.  So many of these people look for true contradictions: if there are true contradictions, then there will be arguments that have contradictory premises, which are all true, but nonetheless a false conclusion.)