Where does the term “ember days” come from and What does ember days mean?

Three days (Wednesday, Friday, and Saturday) of fasting observed quarterly in the Roman Catholic and Anglican churches.

Though the first is but a week after Ash Wednesday, the term ember has no relationship to the ashes of a fire.

It is, in fact, only a corruption of the Old English word ymbrene, meaning “quarterly,” or “seasonal,” for the periods of fasting celebrate the four seasons, spring, summer, autumn, and winter.