There is really no one who readily comes to mind lately of whom I would consider as being a reliable student of Bible prophecy. That sounds like a very sad indictment on those who profess men of God and are supposed to be teaching those who are yet uneducated relative to the word of God the correct interpretation of the scriptures. That statement of course does not apply to most of those who claim to be men of God. Nevertheless, there are still large number(s) of those who claim to be Christian pastors that statement applies to?
All that I have seen thus far are nothing more than theories of one sort or another from most of those who are Christian writers and profess to know the truth. The facts of the matter are that there are still so many that are so far off the mark that it really is quite unbelievable. Of course, all that the majority of these alleged men of God teach is just something that is so far off into the future that by the time the dates they have set come about, most of what they said in their writings, would have forgotten about by the time the dates they have set comes around anyway. That always seems to be the case when their writings prove repeatedly to be just so wrong that there is really no point at all in discussing what they are alleging in the first place.
Therefore, what we really need to be concerned with is what are happening now and not what some men think is going to happen well within the future, when 9 times out of 10 those said same men/women are usually wrong anyway.
There are several indications in the word of God relative to just how certain events relative to the remainder of the Bible prophecies are going to pan out. What I mean by that is that there are certain events that must take place, say for example before the Lord returns back onto the earth. However, there is absolutely no indication whatsoever relative to just when, or as to the timing, of when those said same events are going to pan out. That is, there are no dates at all in the word of God that I am aware of even after having read the Bible from cover to cover numerous times over the forty years that I have been a Christian. Therefore, those who are now coming forth with this date or that date, such as the 21st of December 2012, indicating that there is going to be some form of a paradigm shift are so wide of the mark that it is really quite laughable.
Accordingly, my best advice would be to ignore these sensationalists, as all that they are seeking to do is to attract attention to their respective causes with nothing more than blatant scaremongering. Concluding, date setting is wrong and those who usually indulge in this satanic practice do so for no other reason other than for their own financial benefits. Keep well clear of them at all costs.