What is the significance of 1946-02-14 08:34:56?
I heard that it was the day ENIAC was revealed to the world:


  The completed machine was announced to the public the evening of February 14, 1946 and formally dedicated the next day at the University of Pennsylvania


The theory being that there were no "files" in existence prior to that date.

With regard to the time, 0x4F3AFDB0 (from Finder.h above) mod 86400 (seconds in a day) is 2096. 2096 seconds after midnight is 12:34:56 AM. This is almost certainly the intent: that it reads "123456" on the specified day when time zone adjusted.