"Mr. Omega" is a cute idea, but I still don't get why the cabbie's clock says after midnight, but then he talks to his passenger as though he remembered to change it. Shouldn't his clock say 1:00 then?
He did remember to change it. Both his clock and Mr. Omega's watch say midnight, but the time is
actually 11:00PM, since all the clocks sprang forward. To me, that's a bit of a plot hole - it leaves Mr. Omega an hour in which to fix his mistake, though since he seems to have killed the cab driver in order to get the information, he might not be able to.
While I do like the story in general, it's a bit Terra-centric for my taste, in that a third of the trigger for the collapse of the
entire Universe is ... an Earth human, while another third is a location on Earth!
Similarly for the choice of midnight; how does an arbitrary instant in the rotation of this utterly insignificant little blue-green planet (and that only has significance to - at first approximation - one twenty-fourth of its ape-descended life forms) relate to the destruction of our entire dimension?
I am going to put it down to the flash format, since while 10:27:48 (in digit form) probably has the same word count as 'midnight', the explanation of how that time is arrived at (and a justification of the other factors) could be ponderous.