Believing in Mashiah's Coming Every Day

In the Family First supplement of Mishpacha Magazine, there was an interesting article in the fiction section called "The Critical Countdown".  It told a fictional story about how a select group of people "knew" that Mashiah was coming today and how they started spreading the word to more and more people.  He would only come when 600,000 people believed in his coming that day. 

I don't know of any source to this concept of 600,000 people believing in one day, which is likely why it's in the fiction section.  Nevertheless, I liked the article and thought it was a cute way of making an important point.  The point of the article, I believe, is to spread awareness of the obligation to believe in Mashiah's coming any and every day.  As the Rambam writes, whoever doesn't expect his coming, not only denies the validity of the prophets, but even that of the Torah and Moshe Rabbeinu. 

Even though we expect his coming every day, we are further encouraged from signs and messages that are delivered to our world.  Along with other world events, dreams seem to be a common delivery method.  The HaMikdash blog just posted one, where the deliverer is a direct descendant of David Hamelech.