What is significant about May 6, 1978 at 34 minutes past noon.
Your riddle, similar to "The year is 1978, thirty-four minutes past noon on May 6th, what is the significance" is a test of lateral thinking, some call it "thinking outside the box." One's first instinct when trying to solve this might be to look up the date, trying to find a significant event that took place - that would be "thinking inside the box" or vertical thinking. In actuality the significance of the sentence is numerical. If you change the words that are numbers into digits you can get 12:34, 5/6/78
If you really want to push it, you could also get the 0 from 12:00 and the 9 from 1978, giving you all the digits to make 0123456789.