I have a page here from the Yated Neeman newspaper in New York from the end of Cheshvan 5776, with a very important column about waiting for Moshiach. Since there is much confusion about this issue, I will share some of what the writer, Avrohom Birnbaum, writes, in a summarized adaptation.
Frequently, we hear or read messages that Moshiach is about to come, whether it is this year, at the end of shmitah, this month, any day, and so on. Sometimes these messages are even attributed to a gadol like Rav Chaim Kanievsky shlita, or a mekubal.
With regard to Rav Chaim, it is sad that his name is used as a source for various unfounded and misunderstood statements. One of the members of Rav Chaim's household told Reb Birnbaum that he could be certain that almost everything said in Rav Chaim's name has a chazakah that it is either not true, or taken out of context, by people with vested interests, or distorted by sensationalistic media.
As far as the frequent pronouncements that Moshiach is about to come, the writer says he is profoundly ambivalent about them. Why? Because a ma'amin does not need such announcements. He believes and waits for Moshiach anyway. But not only because of that. It is also because of a great concern that such announcements can actually hurt the belief in the coming of Moshiach among some people.
Reb Birnbaum brings a Chasidic story supporting his position. Around one hundred and seventy five years ago there was a year in which numerous tzadikim and mekubalim predicted that Moshiach would come. R. Eliezer of Dzhikov, a Polish Rebbe, publicly announced at the beginning of that year that Moshiach would not come that year. He explained that despite the predictions, Hashem might decide not to bring Moshiach then (as indeed happened). If so, there was a danger that people, especially simple Jews, might lose their faith in Moshiach. And he could not allow that to happen. On the other hand, if Moshiach would come, what would be the worst thing that could happen? People would say that he was a shakran and not a real Rebbe. It is said that R. Chaim of Sanz, when he heard what R. Eliezer said, praised it, and said 'he saved many Yidden from apikorsus'.
(Adapter's note) There is a similar story about Rav Yaakov Kamenetsky zt"l. I don't recall all the details at present, but I think it was in the context of trying to get someone to close his business on Shabbos. Some people wanted to promise the guy something irresponsible if he did so, such as that Moshiach would come if he would do so and keep Shabbos (two Shabbosos?). Rav Yaakov objected and said that it was not proper to do so, and that the man could lose his faith if and when he would see that what was promised did not happen. The bottom line is that we cannot, it is improper, to build Yiddishkeit with falsehood, and irresponsible, and unfounded claims and predictions.
Another version of this perversion is in form of a revelation allegedly via an autistic child or similar. Such scams should also be ignored.
Such circulating predictions, rather than indicating a strong belief in the coming of Moshiach may actually indicate the opposite. A true maamin has such a strong belief that he has no need of such dubious pronouncements to supposedly be mechazeik him.
May we be zoche to the coming of the true Moshiach bikarov.