"Jeeez, is March National Truth Movement Dead Horse Month?"

Searching on Google for something, I found this expression new to me.

Jeeez, is March National Truth Movement Dead Horse Month?

As there's nothing else on the page that helps understand the phrase 'dead horse month', I went back to search and found Terry Breverton's The Pirate Dictionary and other sources.

Q: Do we still use the idiom 'dead horse month' today? I could find no other such instances yet.

I found this on Yahoo Questions which answers your question specifically; however, I'm unsure if it is a valid response. Interesting nonetheless.

A dead horse was the seaman's term for the first month at sea, a month for which he was already paid and spent the money soon afterwards. To the seaman, with his money gone, he was working that first month 'for free.' To mark the end of this 'dead horse' month, the crew would make an effigy of a dead horse, beat the thing, and dump it overboard in celebration. To officers on the ship, beating a dead horse described the difficulty in getting the crew to do any extra work during this first month at sea.

Let's pick it apart a bit:

"Is March National Something Month?" Means "Is March a month officially consecrated to the celebration or memory of Something?"

The Truth Movement is some sort of 9/11 conspiracy theory organization, presumably.

"To beat a dead horse" is an common idiom for wasting time on a futile and already failed effort. Eg. in this case the mission to show the "sheeple" that 9/11 was an inside job.

So, the author is suggesting that March was a month during which the Truth Movement was particularly vigorous in advancing their ideas in the United States.

The source text is actually formed from a fusion of two common idioms: that of beating a dead horse and that of a National Something-or-Other Month.

The practice of observing or commemorating months is still very much alive and well: http://en.wikipedia.org/wiki/List_of_commemorative_months http://en.wikipedia.org/wiki/List_of_observances_in_the_United_States_by_presidential_proclamation

(Note that International Something Day/Month/Year is also common. The United Nations is still busy issuing observances)

A look at Google Ngrams is sufficient to show that our poor dead horse continues to suffer.