If you don’t do an activity very often, then you can say that you only do it once in a blue moon. We use this expression to emphasize how rare or infrequent an activity is. The activity could be infrequent due to cost, convenience, preference, etc.
This expression is somewhat casual, so it is best suited for informal contexts. For example:
- My cousins live 6 hours away so I only see them once in a blue moon.
- I eat meat once in a blue moon, but I generally prefer a diet based on fish and vegetables.
A. Do you like going to concerts? I have an extra ticket to a local artist’s show tonight. It would be fun if you joined me.
B. Once in a blue moon, I’ll go to a concert if there’s an artist that I really like. It’s not a regular occurrence, so I’d love to go tonight! Thanks for the invite.
Did you know? This expression is similar to the idiom “every now and then,” which is another way to say that you do something infrequently.