Ember days are days of prayer, fasting and ordination. It is a time to pray for bishops, priests and deacons, and - more recently - all Christians in their vocation. And it is common practice - it used to be a universal practice - to ordain persons to the clergy on those days.

The Ember Days occur on the Wednesday, Friday and Saturday of what I will call the "Ember Week." There are four Ember Weeks per year. They are:

1. The week following the third Sunday in Advent;
2. The week following the first Sunday in Lent;
3. The week between Pentecost and Trinity Sunday;
4. The week following the Feast of the Holy Cross (September 14).

Some claim that the name may come from the Anglo-Saxon ymb-ren - a circuit or revolution; something that recurs. And some claim that the word comes from the German quatember, which is a corruption of the Latin quatuor tempora - "Four Times."

Here is an odd little mnemonic that was once used to remember when the Ember Days fell. Note that while I define (above) the Ember Week in Advent as the week following the Third Sunday in Advent, it would also be accurate to say that it falls during the week following the feast of St. Lucy, on December 13, which is what this rhyme references:

Translated into English:

I've taken the liberty of translating more loosely for the purpose of rhyme: