Modul 5: Idiom 45: Once in a Blue Moon

Once in a Blue Moon

Hi. Let’s take a look at the Idiom, ‘Once in a blue moon.’ This idiom is used as a way to describe something that happens very rarely.

So what is the origin of this idiom?

What is a blue moon? A blue moon is the second full moon in a calendar month. Usually, we see one full moon each month, but occasionally we’ll see two full moons within the same month; although, this only happens every 32 months. Quite often the moon appears bigger as well.  The idiom has been around since the 1800s referencing this rare phenomenon.

Take a look at our illustration.

Can you see what the moon is holding? The moon is holding a ‘second sign’. Because of this, we know that this is a blue moon because blue moons are second fullmoons in the same calendar month. Also, can you see how big the moon is? What are the people doing on the hilltop? They are pointing at the moon. They aren’t used to seeing blue moons because they happen so rarely. They have gone to the hilltop to view the occasional – not very usual – sight.

Here are some examples before we go to the concept questions…

“My girlfriend goes to university in Wales so I only ever see her once in a blue moon now.”

“Once in a blue moon, mum lets us stay up past our bedtimes to watch a movie.”

“I’ve complained that we only get performance reviews once in a blue moon, and now the boss is constantly checking up on me!”

“Freddie’s Café food is horrible although, once in a blue moon, they’ll have something nice on the menu.”

“I used to watch a football match every Saturday, but now I watch them once in a blue moon.”

Great.

Let’s look at some situations and check your understanding:

1. Nicole represents her local running club at competition level.  She runs three times a week to keep on top form.  Does Nicole run once in a blue moon?  No.  Nicole runs very often.

2. Barry’s grandparents live in Australia.  It’s very expensive to fly there, so he only sees them every ten years or so.  Does Barry see his grandparents once in a blue moon?  Yes.  There is a long time between their visits.
3.  Frank loved classic cars.  He saw an advert for a 1965 Ford Mustang going cheap in his local newspaper.  “I must buy this,” he thought. Was this a once-in-a-blue-moon opportunity?  Yes.  Many classic cars are very rare, so you often have to wait a long time to find one on sale.
4. Sarah’s friends were round for dinner.  After dinner, her husband got up to wash up the dishes.  Sarah’s friends were most impressed.  “Don’t be fooled,” said Sarah, “he only does it once in a blue moon!”  Did Sarah’s husband wash the dishes often?  No.  He was just creating a good impression for her friends.
5. Dwane and Anita were astonished to see a leopard on their African night safari.  “You’re very fortunate,” explained the guide, “It’s hard enough spotting a leopard on safari during the day, let alone at night.”  Was this leopard sighting a once-in-a-blue-moon experience?  Yes.  As leopards are so well camouflaged, it is very rare to see them at night.

Great. Now go and practise. See you soon.