If two full moons a month equal a blue moon...

Dear Matt, Purveyor of Knowledge, Great and Infinitesimal: While perusing my 1997 tide calendar and looking ahead to the tide fluctuations in the coming months, I noticed in October that there re two new moons in the same month. Now I know when two full moons occur in the same month, it is commonly referred to as a “blue moon, ” hence the term “once in a blue moon” Is there a similar name or term for two new moons in the same month? — I. Flo Freely, Solana Beach

Let’s see.... One blue moon every six years times the diameter of Earth, divided by the distance to the sun, times pi, divided by one double new moon every six years, times January 31,1999, date of the next blue moon, equals...no.