A second full moon within a calendar month is referred to as a blue moon, and that is today!

For the first time in almost 20 years, a bright "blue moon" will grace New Year's Eve celebrations worldwide. (Take a moon myths quiz.)

If the skies are clear, revelers looking up at midnight will get an eyeful of the second full moon of the month—commonly called a blue moon. The last time a blue moon appeared on New Year's Eve was in 1990, and it won't happen again until 2028.

A blue moon isn't actually blue—as commonly defined, the name reflects the relative rarity of two full moons in a month and is linked to the saying "once in a blue moon."

National Geographic

So, happy new years and enjoy your once in a blue moon

The blue moon it hangs over Dublin and the river runs up Spancil Hill

Significantly it would appear, that time has actually come,

Nice piece of information, that was something I was not aware of.

I Have been hearing that old saying "Once in a Blue moon" for most of my 72 years. But this is the first info, I've heard of what it meant!

Happy New Year to All!

Cheers:

Thank you for confirming what I had wondered, but being too lazy to look at the nearest moon calendar over this month, wasn't quite sure. Still I was expecting the Full Moon to be some time around NYE, because I saw it rise in a beautiful golden yellow over Rayong on Dec 1st the first night I got back here from Australia, and it was right there on the horizon looking from the restaurant I have since frequented around every second night, if not more. Lucky I had my camera with me at dinner.

Then again last night, back at the same restaurant up the street, at the same table, there it rose again, that yellow Moon in the sky. I presume that if last night (NYE) was the Blue Moon, then the yellow Moon I saw on the 1st might have been a night prior to full, as I believe I remember there being something like 29 odd days in the Moon cycle, so that would have seen the first Full Moon for December on the 2nd?

Still, those two yellow Moons (the second being a Blue Moon even though it was yellow), seemed to coincide so well from the view from that same restaurant at almost the same time in the evening, of around 18:30, almost like clockwork, even if Dec 1st was not actually truly Full. I was both nights that counts for anything?

Thanks for the clarification on last night's Moon status.