Torg T.R. is right...the JWs deny that those were ever real, concrete prophecies, but they certainly were.
When the dates have come and gone without the prophesied events taking place, the Watchtower Society has given new, "spiritual" or "symbolic" interpretations. Just one example: When Armageddon didn't break out and the world as we know it end in 1914 (as had clearly been prophesied in their literature), "new light" revealed that Jesus ascended his throne IN HEAVEN in 1914, invisibly extending his reign over the earth from that time forward.
To Fernando: I am not a JW, but I have to "call" you on some assertions you make:
1) First of all, the JW "New World Translation" is not "heavily flawed"; actually, it's a pretty accurate translation from the Hebrew, Aramaic, and koine Greek in which the Bible was written; its biggest flaw, in my opinion, is that they try to translate word-for-word, using one English word consistently to translate the same Hebrew, Aramaic, or Greek word, and that really can't be done; in fact, you can't translate word-for-word like that from such a modern language as, say, Spanish or French to English, let alone from an ancient language to English.
2) And Fernando, my friend: Where in the world, in ANY piece of JW literature, did you read that "Pleiades" idea? There are groups that may have suggested such a thing, but I can't think of anything more foreign to JW teaching.
3) "Torture stake" is probably a better translation for the tree on which Jesus was executed; it's highly unlikely that it was an upright stake with a crossbeam, as it's usually pictured; that cross, along with the idea of the Trinity, is just one of the things promoted by the pagan Emperor Constantine primarily for political, not religious, reasons. Incidentally, when Constantine was baptized (on his deathbed), it was by the Arian (nontrinitarian) Bishop, Eusebius of Nicomedia!
What do I think of the JW prophecies? I lump them in with all the others; i.e., Nostradamus, Mayan calendar, etc., etc. No more questionable, no less.
Jehovah's witnesses are well meaning people but the have completely misinterpreted the Bible. Their New World Translation is heavily flawed.
They use to teach that God ruled the galaxy from the Pleiades star system.
They have replaced the cross with a torture stake.
I went to one of their meetings a few years ago and it was boring. They way they teach is like a school test. Question and answer form.
They think only 144,000 people will make it into heaven too.
Not just their prophecies, but my father and step mother (and her children, and grand-children) are (all) Jehovah's Witnesses, they all believe that only 144,000 people are going into Heaven, and it is 12,000 of each of the old Jewish tribes that are going, yet upon some of my last visits (I am almost 20, I have only seen my father once since my 18th birthday) they kept telling my brother and I we are going to hell for things like, how my brother is spoiled, though he used his own money to by his hard to find size 15 shoes, and I going for reading LaVey's books (though I now know most all of his work is plagiarized, and all of his work is very unoriginal) and both of us are going to Hell because of bull crap of like, that we like The Lord of the Rings and Harry Potter, and they use 'sorcery which is evil' and so forth!
Edit: Fernando C- I know, 2 hours of tone-deaf singing (my father was the most base style one of them all out of every meeting) and monotone speaches and prayers. They also did the Q & A stuff from the Watch Towers, the small children and elderly took the longest at about 10 minute to give their answer! I have been to 2 of their conventions (or maybe is was one.... I haven't been a JW for about 5-6 years, so I don't remember too well) in Richland Washington, and going to Kingdom Halls, one in Washington (when they visited JW freinds for a few days while my father picked us up for visitation) and 2 different ones in Montana, 1 in Missoula. I have a number of JW friends from the ones in Montana, but their beliefs are just very funny yet morbid!