Idiom of the day - Once in a blue moon

ONCE IN A BLUE MOON - when something happens very rarely

Eg.: All us college friends used to meet all the time. Now we just meet once in a blue moon.
Eg.: The Hollywood actor Ben Affleck is seen once in a blue moon at public events.
Eg.: The food of this restaurant is always served hot. It may happen once in a blue moon that it may be a little cold.
Eg.: "Does your husband give you gifts?" "Not so much, it happens once in a blue moon."