once in a blue moon

Every once in a blue moon, our youngest daughter Amma has a Sunday soccer game; in that case, you’ll find me on the sidelines at her game.

It's a phenomenon - or, to use Chappell's terminology, a Femininomenon - that only occurs once in a blue moon.

As blue moons are not that common, it's thought where the phrase "once in a blue moon" comes from.

Kovacic's 64th-minute strike against Luton was one of those goals you see a defensive midfield player score once in a blue moon - no pun intended.

If it were not for the undemocratic and unfair electoral college, we could all go to sleep since Trump will lose decisively in the popular vote once again as he and the Republican candidates always do except for "once in a blue moon."