Jesus was referring to the generation that would be alive at the time that the event that his fig tree parable refers to would occur. It is widely believed that this parable refers to the rebirth of the nation of Israel (which occurred in 1948). generation from the greek
genea 1074
1) fathered, birth, nativity
2) that which has been begotten, men of the same stock, a family
a) the several ranks of natural descent, the successive members of a genealogy
b) metaph. a group of men very like each other in endowments, pursuits, character
1) esp. in a bad sense, a perverse nation
3) the whole multitude of men living at the same time
4) an age (i.e. the time ordinarily occupied be each successive generation), a space of 30 - 33 years
33 years would be 1978.
First of all, there are various opinions as to length of the generation that Jesus referred to. I have often heard 40 years, but obviously that still doesn't bring us up to present day. However, what you are referring to is the length of what we call a "generation", while Jesus simply said that the generation that saw the "fig tree" event would not pass away before all of the rest of the prophecy occurred. Well, if even one person from a particular generation is still alive then I would propose that it is reasonable to say that that generation has not yet passed away. Given a 110 year or so maximum lifetime, we could be looking at somewhere around 2058 as the outside limit of this prophecy.
Of course, this is all conjecture and opinion. None of us know the ultimate answer to any of this. The primary point was to be prepared, spiritually and physically, regardless of when "the day of the Lord" comes.