Shabbos Rosh Chodesh Haftorah Question
It's been a long time since I've posted one of these liturgical quizzes - or for that matter much of anything besides my bi-weekly editions of Musical Monday. But here's an interesting question I thought up yesterday, relating to the special haftorah which was read for Shabbos Rosh Chodesh:
As it happens, this haftorah is actually ever read on just five out of the twelve months of a standard Jewish year. For which five months can it be read, and why is it never read on each of the other seven? Post your answers in the comments; a special Elie's Expositions no-prize to whoever gets the complete solution first!